Leading Email eDiscovery Software for Legal Professionals

A professional email collector must support a wide range of file formats and service providers. It should also be optimized for speed to efficiently handle large volumes of data in a reasonable time. And it must do all it can to preserve data integrity during the collection process and report issues when they occur.

Support for Most Email Formats and Services

Local Email Storage

The following file formats are supported:

• PST, OST, and MSG files from Microsoft Outlook
• OLM files from Outlook for Mac
• Mbox files from Mozilla Thunderbird, Google Takeout, etc.
• EML files, used to store a single email message
• Maildir files in native format from an IMAP server
• Apple Mail (EMLX) in native format

Aid4Mail can process PST and MSG files with or without Outlook. It’s noticeably faster with Outlook, and you can further reduce processing time by using native filtering.

Aid4Mail also integrates an advanced email parser that can accurately extract emails from corrupted mbox files. This is essential because of the prevalence of damage in those types of mailboxes.

Note that some competing products claim to support EMLX files from Apple Mail. Our tests found those claims to be misleading, resulting in significant data loss. We’re confident that Aid4Mail is the only eDiscovery collection tool that can accurately extract Apple Mail messages with all their contents and metadata.

Microsoft Outlook and Exchange

Aid4Mail provides several methods to collect emails from Microsoft Outlook and Exchange accounts. You can access the account through an Outlook profile (using MAPI), the IMAP protocol, or Microsoft’s Graph API. Each method offers native pre-acquisition filtering, which can significantly speed up email collection.

Note that, to collect mail from Exchange Online Archives, and Public and Shared folders, you must use an Outlook profile.

Webmail Service Providers

Collect emails from all webmail service providers that support the IMAP protocol. These include Microsoft 365 (formerly Outlook 365), Gmail, Yahoo! Mail, AOL, etc. Aid4Mail can also access Microsoft and Gmail accounts directly through their respective APIs. Fast native pre-acquisition filtering is available for all these accounts.

Aid4Mail supports the OAuth2 login protocol, enabling secure access to your (or your custodian’s) webmail accounts.

Remote Authentication

Collecting email from your custodians’ cloud-based accounts is made easier with Aid4Mail Remote Authenticator—a free stand-alone utility that they can download and run without installation. It enables the account owner to grant Aid4Mail secure, temporary access to their email service or IMAP account, without providing full login credentials or needing a copy of Aid4Mail.

Archival Formats

Aid4Mail can extract mail from the following archival formats:

• Google Takeout
• Google Vault exports (zipped MBOX files)
• Mimecast exports (zipped EML SJF or EJF files)
• Proofpoint exports (password-protected zipped EML files)

Note that you’ll need the Investigator or Enterprise edition of Aid4Mail to process Google Vault exports, and the Enterprise edition to process Mimecast and Proofpoint exports.

Incremental Processing (Differential Acquisition)

Processing errors typically relate to:

• Server timeouts, overloads, or bandwidth limits
• Lost internet connections
• Insufficient free disk space on the target drive, etc.

This is where incremental processing (differential acquisition) comes to the rescue. Aid4Mail identifies the emails that have been added since (or missed during) the last cycle and processes only them. In other words, it lets you pick up where you left off; no need to start all over again.

Aid4Mail offers incremental processing for all supported email formats and performs it natively, server-side, when collecting from cloud services like Microsoft 365, Gmail, and Yahoo! Mail.

This ability is usually missing in other tools. It is a significant time-saver because Aid4Mail can determine whether it has already processed an email before downloading it. As a result, resuming an aborted acquisition is very fast and reduces the risk of reaching those dreaded service-bandwidth limits.

Built for Speed

Aid4Mail’s speed optimization directly addresses the eDiscovery need for timely data collection, enabling legal teams to process terabytes of email data swiftly. This capability is essential for meeting the critical deadlines encountered in litigation and regulatory compliance cases, ensuring that no valuable time is lost in the preliminary stages of discovery.

Processing Local Files

Local processing in Aid4Mail is highly optimized for speed without sacrificing reliability or accuracy. When processing local mailbox files, Aid4Mail can parse, collect, and convert emails up to 10 times faster than its competitors. This means that an email collection taking a week to complete with a competing tool would require just one day with Aid4Mail—a considerable time-saving!

We conducted speed tests using a standard ASUS laptop (2022 model with an AMD Ryzen 9 5900HX processor and an internal SSD drive). Our tests included converting the publicly available John Podesta email collection, a 5 GB file containing 50,887 emails.

In our first test, Aid4Mail converted the Podesta emails from mbox to Outlook PST in 2 minutes and 59 seconds. That’s a rate of 284 emails per second!

In our second test, Aid4Mail converted the same data from PST to mbox in 8 minutes and 10 seconds, a rate of 103 emails per second. The slower performance in this second test is due to additional processing to preserve metadata and improve conversion accuracy. Despite this, Aid4Mail still performed faster than competing tools. With a high-end computer, you can expect even better results.

Note that you can download the Podesta mbox file from the internet for free. Use it to test your current eDiscovery tool and compare its performance with Aid4Mail. We’d be happy to provide you with a download link if you can’t find it. Just contact us with your request.

Remote Accounts

Aid4Mail is optimized for cloud-based email accounts, offering two time-saving features often missing in other tools. Both involve native, server-side processing of emails and are covered in the following sections:

1. Incremental processing
2. Native pre-acquisition filtering

With these capabilities, Aid4Mail can collect emails up to 100 times faster than tools without them.

Concurrent Processing

With Aid4Mail Investigator and Aid4Mail Enterprise, you can run multiple processing tasks simultaneously, taking full advantage of your computer’s hardware and saving more time. Consider a scenario where you need to collect email accounts from several employees under investigation, or one where you need to gather multiple source formats from a single custodian.

For example, you might need to collect data from a custodian’s Microsoft 365 account, Gmail account, local Thunderbird files, and archived EML files, and combine them into the same batch of target PST files. With Aid4Mail, you can set up the project in advance and let it run overnight so that no time is wasted.

Alternatively, you may have four tasks that use the same input but require different filters, with the results output to separate folders within the same PST file. In Aid4Mail, all four tasks can be run concurrently, and unattended, while you are working on something else. You can see an example of this in the screenshot below.

Data Integrity

Data integrity and preservation are essential parts of legal discovery. Without them, you risk compromising your case due to loss of evidence. Large mbox files and Outlook PST files often contain data corruption, and some email client programs worsen the situation by deviating from format standards in undocumented ways. Even fully intact email is vulnerable to data loss during collection, format conversion, and target storage.

Aid4Mail stands out from other eDiscovery software in its ability to maintain data integrity. It is built on a foundation of 25 years of email processing, significantly longer than other email collection tools on the market. Not only does Aid4Mail avoid data loss during processing, but it can usually repair pre-existing data corruption, and work around non-standard file format implementations.

Aid4Mail’s advanced capabilities in repairing pre-existing data corruption not only prevent loss but also ensure that crucial evidence is retrievable and usable in legal contexts. This functionality is particularly valuable when dealing with legacy data, or when ensuring compliance with legal discovery obligations where the integrity and completeness of evidence are paramount.

Folder Names and Structure

Preserving folder structures and names during mail collection helps to quickly distinguish between emails like Sent, Drafts, Deleted, Spam, and Received messages. It also reveals how custodians grouped and organized their incoming mail. This makes it easier to sift through extensive email collections and find clues to the most significant messages.

Aid4Mail lets you include or exclude folders during the acquisition process. This can significantly speed up email collection, especially if you can exclude large folders with unnecessary content. However, folder filtering only works reliably when based on an accurate representation of the source account. Aid4Mail provides this.

Aid4Mail excels at preserving data integrity with respect to the email folder structure. It particularly stands out among other solutions when handling Google Takeout files, Google Vault exports, Maildir stores, and local Thunderbird mailboxes. This is because Aid4Mail understands the unique implementations of these formats and is able to work with (or around) them.

Attachments and Embedded Contents

During email collection, certain storage formats have a higher risk of data loss of attachments and embedded content. This concerns formats that don’t store or deliver emails in native MIME format; for example, Apple Mail EMLX files, Thunderbird and RFC 1521 emails with detached attachments, and emails acquired through Microsoft Outlook.

Again, Aid4Mail understands the unique implementations of all these formats. Unlike many email acquisition tools, it handles them correctly and recovers their attachments (as long as they haven’t been moved or deleted).

Cloud attachments

Also known as modern attachments, these are files that are hyperlinked from an email but hosted by a cloud-service provider.

Like many email eDiscovery tools, Aid4Mail is able to collect files attached to an email in the traditional manner. However, it goes much further than most, into new territory—Aid4Mail enables the collection of cloud attachments and their metadata from any of its supported formats. You can decide whether to collect multiple document revisions or only the latest version, and set a size limit for maximum efficiency.

If access to a cloud attachment requires login credentials, these can be provided to Aid4Mail for both Microsoft and Google accounts. Aid4Mail uses secure OAuth2 authentication, and also supports the remote authentication of custodian accounts.

Aid4Mail is among the very few email collectors that support cloud attachments and, at the time of writing, the only one to collect from both Microsoft and Google’s platforms.

Header Metadata

If processed incorrectly, specific email formats and protocols are susceptible to loss of header metadata. This occurs when collecting messages through Outlook’s MAPI protocol or accessing MSG, OST, and PST files through third-party DLLs.

We’ve seen results from eDiscovery collection tools that lost important information, including:

• Email addresses
• Sender’s time zone
• IP address
• Server relay information
• Original Message-ID
• Thread index

This level of data loss is potentially disastrous when performing eDiscovery email searches. You can easily avoid these serious issues by using Aid4Mail.

Email Status Information

Email status information tells you about the actions taken on a received message. For example, whether it was read, replied to, or forwarded. It also indicates the status of an outgoing message, whether it is still a draft, unsent, or sent. Emails can also be flagged (or starred), and marked as double-deleted. This is crucial information as it provides valuable insights into the lifecycle and interactions associated with an email.

Some email acquisition tools do not collect email status information at all, or only partially collect it. Aid4Mail stands out again by preserving this important data, whether the emails are obtained from cloud-based accounts or from local stores such as Google Takeout, OST, and PST files.

Format Errors

There are many different email client programs and cloud-based systems for sending messages. Unfortunately, some don’t fully respect standards, or they contain bugs that produce email format errors.

We have encountered a considerable number of these format errors during our many years of creating email solutions, even from companies like Microsoft and Google. The result of our extensive experience is that Aid4Mail can fix many of these errors, ensuring emails and their metadata render without data loss.

Enhancing Legal Outcomes through Technology

By leveraging Aid4Mail’s advanced email parsing and conversion technologies, legal teams can ensure that the data integrity of emails is maintained from collection to court presentation. This includes preserving the original formatting and metadata of each email, essential for establishing the authenticity and context of the evidence. Aid4Mail therefore acts as a bridge between the technical and legal domains, providing a seamless transition for email data into the legal review and litigation process.

Progress and Error Reporting

Aid4Mail provides detailed progress information and error reporting to ensure a smooth experience. You can track the progress of your task through real-time indications of both the amount of data processed and the estimated time to completion. You have access to a detailed progress report and, when necessary, an error log. The software displays various counters indicating how many folders and emails have been collected, excluded by your filter criteria, and failed due to errors.

Aid4Mail continues to lead in accurate, high-fidelity email conversion. Its advanced parser extracts complete message data—including metadata, headers, body, and attachments—into formats suited for legal and forensic review. Our  HTML email viewer empowers reviewers to interact with email datasets more effectively than ever with real-time search, tagging, and sorting.

Data Integrity and Preservation

During the acquisition, review, or production phase, a professional email collector must usually convert email from one format to another. If not performed correctly, significant data loss can occur. Certain format conversions are more prone to this than others, notably conversions between Outlook files (PST, OST, and MSG) and MIME formats (mbox and EML).

Data loss can affect various aspects of email data. The following may be missing altogether:

• • Embedded images, traditional attachments, and cloud attachments
  • Original email SMTP header and Message-ID value

• Sender or recipient email addresses
• Message status information (unread, read, replied, etc.)

Other parts of the email may be present but incorrectly converted:

• Folder names
• Dates, especially time zones

Data loss is sometimes unavoidable due to the constant evolution and complexity of mail systems and formats. However, it can be mitigated by using a specialized and up-to-date email discovery tool like Aid4Mail.

Aid4Mail’s conversion engine boasts over 25 years of expertise and is updated regularly to respond to changes in the products it interacts with. In conversions between MIME and Outlook formats, Aid4Mail outperforms most of its competitors. It is one of the few tools that can convert native Apple Mail files (EMLX) without any data loss, as well as Thunderbird and RFC 1521 emails with “detached” attachments.

We know how to preserve data integrity, that’s how we built our reputation!

Email Backup Option

Sometimes, format conversion fails due to issues with the target API (typically with MAPI or IMAP). When this happens, it is essential to have a backup of the source email for preservation purposes.

Aid4Mail stores email backups locally under a folder structure that mirrors the source account. Emails collected through Outlook, or from PST and OST files, are backed up as MSG files. Emails from other formats are backed up as EML files.

Journaled Emails

Organizations use email journaling to create and maintain a secure and tamper-proof record of all email communications. They do this to satisfy compliance and legal requirements, as well as for data retention and disaster recovery.

A journaled email comprises:

1. The journal envelope, containing:
   1. A header with essential metadata such as sender and recipient addresses, timestamps, and transport information.
   2. A body with the journal report that typically includes sender and recipient addresses (including Bcc and distribution list recipients) and the original Message-ID value.
2. An attachment containing the complete, unaltered original email message.

In an investigation, journaled messages present several challenges. For example:

• Depending on the email client program, the original message is shown as an attachment, and so can only be accessed after extraction.
• When using fielded searches on header metadata, important information only available in the original email header, or journal report, may be missed.

Aid4Mail solves these challenges with two unique features:

1. Removes the journaling envelope during collection.
2. Preserves essential metadata by adding the sender, and all recipient addresses, from the journal report to the original email header.

Review and Ingestion Formats

Aid4Mail supports all major email review and ingestion formats used in eDiscovery, including PST, PDF, CSV, EML, mbox, HTML, XML, JSON, and plain text. With the HTML export, users gain a powerful browser-based email viewer that handles massive datasets with ease—supporting sorting, filtering, metadata searching, and tagging.

Emails are often converted to PDF files, a convenient format for presenting evidence in court or sharing with others. Aid4Mail offers standard PDF as well as variants—archivable PDF/A and press-ready PDF/X. You can insert Bates stamps into PDF pages, embed attachments in their native format, password-protect files, and more.

Convert emails to HTML and use Aid4Mail’s powerful browser-based email viewer. View over 50,000 emails instantly. Search metadata fields like subject, sender, or folder. Sort columns. Tag and filter emails for legal responsiveness, privilege, or issues. Perfect for use in legal discovery, forensics, or audits.

You can host the email viewer for online access or share the portable folder securely for offline review. Attachments remain stored separately and are accessible via links. Fully customizable HTML structure supports your specific review workflows.

Data Extraction

To perform metadata and attachment analysis in your investigation, you will need to extract relevant data from emails. Aid4Mail offers flexibility and complete control over this process. Its high-end email parser can reliably extract:

• Traditional email attachments
• Cloud attachments
• Embedded message content (like inserted pictures)
• The message in plain text format
• Available message metadata
• Unique email identifiers, including PR_ENTRYID and EDRM MIH values
• AI analysis of the email. For example, this might be an automated summarization, translation, or extraction of specific criteria, depending on the prompt used.

Aid4Mail’s configuration editor enables you to choose exactly which data to extract.

Extracted attachments and embedded contents are saved in their native formats (except for native Google documents that are converted to their Microsoft counterparts). Metadata and message text are saved in CSV (comma-separated values) files, either database-compliant or Microsoft Excel-compliant, or as TSV (tab-separated values) files.

Aid4Mail specializes in emails and their attachments and can collect and find mail that other eDiscovery tools miss—it is an industry leader in this domain. Due to this specialization, Aid4Mail’s workflow differs from traditional solutions like OpenText Encase, Exterro FTK, and Magnet Axiom. By focusing on its primary tasks, collecting, filtering, and converting emails takes a fraction of the time needed by other eDiscovery tools.

Here’s why:

• Once configured, Aid4Mail can operate without user intervention. There is no manual review stage to interrupt the streamlined workflow.
• Aid4Mail’s native pre-acquisition filtering can significantly reduce the volume of data downloaded from IMAP accounts and mail servers like Microsoft Exchange, Office 365, and Gmail.
• With no review stage between email collection and conversion, Aid4Mail doesn’t need to build search indexes. This saves a lot of time and system resources.
• Aid4Mail’s integration of AI to analyze emails can also eliminate most, if not all, post-conversion manual review.

As a result, you can process terabytes of email data, unattended from start to finish, fast and accurately. And, unlike hosted eDiscovery solutions like Relativity, Everlaw, and LogikCull, the whole process can happen on-premises, so you don’t incur third-party charges for the volume of data collected and processed. This significantly reduces costs.

Aid4Mail offers flexible, searchable formats for examining email collections in your preferred tools. With the HTML export, even large collections—over 50,000 emails—can be reviewed directly in your browser using our sophisticated email viewer.

• PST files in Microsoft Outlook
• Mbox files in Mozilla Thunderbird
• PDF files in Adobe Reader
• HTML files in your browser with tagging, filtering, sorting, and full metadata search
• CSV files in Microsoft Excel
• JSON files in an AI analysis tool
• Plain text files in a text editor

If you cannot cull your email collection to an adequate size, consider transferring Aid4Mail’s output to a comprehensive eDiscovery platform like Relativity, Encase, Axiom, etc. Aid4Mail is an excellent complement to such tools, thanks to its fast email collection, native pre-acquisition filtering, advanced search capabilities, and AI integration.

Aid4Mail’s robust eDiscovery features make it an invaluable tool for legal professionals engaged in civil litigation, compliance, and FOIA requests. Designed for both efficiency and precision, it provides tangible benefits in real-world legal scenarios. Here, we explore some of the practical applications of Aid4Mail, illustrating how it revolutionizes the way legal teams approach electronic discovery.

Streamlining Civil Litigation

In civil litigation, the ability to quickly and accurately sift through vast amounts of email data can significantly impact the outcome of a case. Aid4Mail facilitates this by offering litigation attorneys and law firms a powerful platform for eDiscovery collection and analysis. By leveraging Aid4Mail’s broad format compatibility and advanced search capabilities, legal teams can efficiently identify relevant communications, even within extensive datasets. This not only accelerates the discovery phase but also enhances the overall strategy by ensuring that critical evidence is not missed or overlooked.

Streamlining FOIA Compliance and Responses

Aid4Mail significantly simplifies the management of Freedom of Information Act (FOIA) requests for public sector entities and organizations governed by public information laws. Its advanced search and extraction capabilities enable swift and accurate identification of relevant communications, facilitating compliance. This streamlined process not only enhances transparency and accountability but also ensures the protection of sensitive information, aligning with legal obligations for confidentiality and data integrity. Aid4Mail’s adaptability across various email formats further ensures comprehensive coverage, making it an indispensable tool for efficient FOIA request handling.

eDiscovery for Small Law Firms

Small law firms, often limited by resources, can particularly benefit from Aid4Mail’s efficiency and user-friendly interface. Aid4Mail levels the playing field, allowing smaller teams to undertake complex eDiscovery tasks without the need for extensive IT support. Its incremental processing and AI integration are a boon for ongoing cases, enabling small firms to stay updated with minimal effort. By reducing the time and costs associated with eDiscovery, Aid4Mail empowers small law firms to compete more effectively, even in cases against larger adversaries.

Corporate Counsel eDiscovery Management

Corporate counsel tasked with managing eDiscovery, for internal investigations or litigation, faces unique challenges. Aid4Mail’s capabilities in handling eDiscovery for Office 365, alongside its support for other corporate email systems, streamline the process of internal data collection and review. By enabling efficient search and analysis of email data, Aid4Mail facilitates corporate counsel in proactively managing legal risks and ensuring regulatory compliance. This protects the organization from potential legal exposures.

Managing Internal Investigations

Aid4Mail facilitates internal investigations by providing comprehensive search capabilities. These allow corporate legal teams and HR departments to swiftly locate and review emails related to internal complaints, misconduct allegations, or policy violations. Aid4Mail’s ability to handle vast amounts of data across various email formats ensures thorough investigations while maintaining privacy and data integrity.

Mergers and Acquisitions (M&A) Due Diligence

During M&A activities, due diligence requires meticulous examination of electronic communications to identify potential legal, financial, or regulatory issues. Aid4Mail can streamline this process by efficiently processing and filtering large email datasets, enabling legal and financial teams to focus on relevant information and make informed decisions faster.

Intellectual Property (IP) Protection and Litigation Support

Aid4Mail helps with IP protection efforts and litigation by enabling precise searches for emails. Particularly for those containing discussions about proprietary information, inventions, or trade secrets. This capability is invaluable for identifying unauthorized disclosures and gathering evidence for IP litigation cases, helping organizations safeguard their valuable assets.

Compliance Auditing

Organizations facing strict regulatory requirements can use Aid4Mail to ensure compliance with industry standards and regulations. By enabling targeted searches for specific terms, dates, or compliance-related content, Aid4Mail helps compliance officers efficiently review email communications and prepare reports. These tasks are essential to ensuring adherence to legal and regulatory frameworks.

Disaster Recovery and Email Migration

Aid4Mail supports disaster recovery efforts by enabling organizations to retrieve and convert email data from damaged or obsolete systems. It also facilitates smooth email migrations between different platforms, or to cloud services, ensuring that critical communications are preserved and remain accessible.

Anti-Money Laundering (AML) Investigations

Financial institutions can use Aid4Mail to streamline the review process of vast email datasets for AML compliance. By efficiently searching through communications, institutions can identify suspicious activities such as unusual transaction patterns or communications with high-risk entities. This ultimately facilitates quicker response times to potential AML violations.

Tax Compliance and Audit Support

Aid4Mail can streamline the process of sifting through large volumes of email data to identify non-compliance with tax laws. It enables auditors to efficiently search for specific terms, transactions, and correspondences related to tax filings, exemptions claimed, and other pertinent information. Easy access to relevant data subsequently leads to more thorough audits and investigations.

Fraud and Evasion Investigation

Government tax offices can employ Aid4Mail to detect and investigate cases of tax fraud and evasion. By analyzing email communications for evidence of undeclared income, false deductions, or other fraudulent activities, investigators can gather the necessary evidence to pursue legal action against offenders.

In each of these scenarios, Aid4Mail stands out as a versatile and powerful eDiscovery tool that adapts to the specific needs of its users. Whether employed to navigate the intricacies of civil litigation, manage compliance and FOIA requests, or enable small law firms to efficiently handle eDiscovery tasks, Aid4Mail delivers tangible benefits that enhance the effectiveness and efficiency of legal processes. Its practical applications in eDiscovery not only demonstrate versatility but also underscore Aid4Mail’s value as an indispensable asset to the legal profession.

Attachment

A traditional attachment is a file of any type that is attached to an email by the sender. An email can have one or more attachments, or none at all. Attachments are included in the email itself, increasing its size, although are not part of the message body.

Cloud attachments (also known as modern attachments) are a newer concept. They are not contained inside the email. Instead, they are hosted by a cloud-service provider and hyperlinked from the email. In some cases, this is done by the service provider because the file size exceeds their attachment limit. In other cases, often with collaborative online documents, it is simply for convenience.

Application Programming Interface (API)

A method of communication between two pieces of software. Using a mail service’s API to access data usually offers benefits over using more general protocols like IMAP. For example, access to additional metadata, native filtering, and reduced bandwidth limitations. Email-related APIs used by Aid4Mail include MAPI, Microsoft Graph API, and Google APIs.

Electronic Discovery Reference Model (EDRM)

A framework that outlines standards for the recovery and discovery of digital data. The EDRM model is used to guide the process of handling electronic data during legal proceedings, including phases such as identification, preservation, collection, processing, review, analysis, production, and presentation of digital evidence. It’s widely adopted by legal and IT professionals to ensure a clear and efficient approach to eDiscovery processes.

EDRM Message Identification Hash (MIH)

A standardized method of identifying duplicate emails across multiple data sets from any vendor platform that supports it. The MIH is an MD5 hash value generated from the email’s Message-ID metadata field. It offers a universal method to recognize identical emails, enabling legal and investigative teams to efficiently manage, review, and deduplicate email collections. This solution enables cross-platform duplicate detection without the need to reprocess data, saving significant time and resources. The EDRM MIH is intended to complement existing vendor-specific deduplication methods, serving as an additional tool for more effective email management in discovery, disclosure, and investigations.

Electronically Stored Information (ESI)

Any data or information that is created, stored, or used in digital form. ESI encompasses a wide range of data types, including emails, documents, presentations, databases, audio, and video files, social media content, and electronic records stored on digital devices like computers, smartphones, and servers.

Email Message-ID

A unique string of characters in the email header, that identifies a message in the context of a particular email conversation or thread. The Message-ID is assigned by an email system when a message is created, and is used to track, reference, and relate individual emails. This helps to manage message threading and prevent duplication. In eDiscovery and email analysis, the Message-ID can be crucial for tracing the origin and trajectory of an email.

Although each Message-ID is unique within its own data set, it may not be so across multiple datasets. The EDRM MIH provides a solution to this problem.

Email SMTP Header

Metadata in an email message, containing detailed routing information. The SMTP header is automatically generated and located before the email message body. Although there is no limit to what can be added to it, key elements include the sender and recipient addresses, timestamps marking the email’s path through multiple servers, and unique identifiers for each server. Email service providers use the SMTP header to authenticate the email sender, and to correctly allocate incoming mail. In eDiscovery, the SMTP header is an essential resource for tracing the origin and path of an email, and understanding the network behavior of email communication.

Email Status Information

Metadata associated with an email that indicates the actions taken on it. For incoming mail, this includes whether the email has been read, replied to, or forwarded. For outgoing messages, it indicates whether an email is a draft, and whether sent or unsent. All emails can also be flagged, starred, or marked as double-deleted.

Exchangeable Image File Format (EXIF)

A standard for storing information as metadata in image files. EXIF metadata is commonly used by digital cameras and smartphones, and typically includes the camera model, capture settings (shutter speed, aperture, ISO, etc.), and the image date, time and location (GPS coordinates). It is useful for organizing and cataloging images, and can be crucial in eDiscovery for verifying the authenticity and origin of photographic evidence.

Fielded Search Operator

A command used to narrow down search results by targeting a specific field or attribute of an email or document. It enables you to search for an element like the sender, recipient, subject line, date, or other metadata field.

Internet Message Access Protocol (IMAP)

An Internet Standard protocol (RFC 3501) supported by most email applications that enables direct access to mail on a remote server. IMAP allows multiple apps to access the same mail account, even from different devices. This feature is the main reason IMAP is generally preferred over POP, an older protocol that requires mail to be downloaded to the device.

Messaging Application Programming Interface (MAPI)

An API for accessing Microsoft Outlook and Exchange. Aid4Mail uses MAPI to read and write to Outlook profiles, and PST/MSG files when the “Process using Outlook” option is turned on.

Multipurpose Internet Mail Extensions (MIME)

An Internet standard for email messages that supports both data and metadata, non-ASCII character sets, multiple fonts, non-textual content, and multiple attachments of various file types. It is an extension of the original Simple Mail Transport Protocol (SMTP).

PR_ENTRYID

A property used in Microsoft Outlook and Exchange to uniquely identify various types of objects within the messaging system, such as emails, calendar events, contacts, etc. It is a binary value that acts as a unique key, allowing each item to be retrieved, moved, or manipulated within the system. This identifier is crucial for developers and administrators working with Outlook and Exchange APIs, or scripting, as it enables precise access and control over individual messaging objects within the store.

Responsive Data

Data that is pertinent to matters of the case (in a legal context) and meets the criteria specified in a discovery request. It can be in various forms, such as emails, documents, images, or other electronically stored information (ESI).

RFC 1521

An early part of the MIME standard that defines support for non-ASCII character sets, multiple fonts, and non-textual content. We refer to this standard when discussing certain types of attachments based on the Message/External-Body subtype format that Aid4Mail supports.

Simple Mail Transfer Protocol (SMTP)

A standard protocol for email transmission. Mail servers use SMTP to both send and receive email messages. Email client programs typically only use SMTP to send messages (to the mail server for relaying), using IMAP or POP to retrieve them. SMTP was created in the 1980s and has since been modified and extended multiple times. The version commonly used today is extensible, with extensions for authentication, encryption, binary data transfer, and internationalized email addresses.

Stemming

The process of reducing words to their base or root form. For instance, the words “running,” “runs,” and “ran” all stem from the root word “run.” This technique is used in search algorithms to improve their effectiveness, by allowing for the matching of word variants with a common stem. Stemming enhances the ability of search engines or text analysis tools to find relevant results when the exact form of a word is not known.

Tokenization

The process of breaking a string of text into smaller units—tokens—usually words or phrases. Tokenization helps to identify key elements in a text. It is fundamental in text analysis and search algorithms, where the tokenized text is used for further processing like indexing or evaluating search queries.

Virtual Machine (VM)

The virtualization of a computer system that provides the functionality of a physical computer and its operating system. With enough computing power, multiple virtual machines can run independently from one another on the same underlying hardware.