Differences Between MailStore Versions

General Information About MailStore Server Version Upgrades

• Before starting the installation, please check whether your current license actually allows you to upgrade the software.
• Before installation, read all details about changes in the relevant versions.
• Make sure you have taken a new backup of your archive. For more information about backing up and restoring MailStore Server, you can find it here.
• Make sure that the system requirements of the server where MailStore Server is installed are met.
• The installation process will automatically remove previous versions of the software. All archives and configuration data will be preserved. You do not need to manually remove previous versions.
• During the installation process, the MailStore Server service is automatically stopped and then restarted. Active archiving profiles may be canceled and appear as failed. If stopping the service fails for any reason, please stop the service manually and restart the installation.
• Carefully review the automatically detected settings during the installation process.
• Upgrades from versions earlier than 9.x to a new main or secondary version (e.g., 5.1 - 5.2) require upgrading the MailStore Client and/or MailStore Outlook Add-in installations.
• From versions 9.x up to 13.x, this is usually only required for main version upgrades (e.g., from 9.8 to 10). Exceptions are specified in the version-specific announcements below.
• For versions 22.x and above, version-specific announcements regarding these upgrades will be added if needed.

More information can be found in the MailStore Client Distribution and MailStore Outlook Add-in Distribution articles.

• The following version-specific upgrade announcements are cumulative. Therefore, you should also read the announcements for all version numbers between yours and the one you will install.
• For versions not explicitly listed here, the upgrade announcements of previous versions apply accordingly.

MailStore Server 26.2.1

19/05/2026

• Support for the latest Microsoft Office 365 update (Exchange Server 15.21).

MailStore Server 26.2

29/04/2026

• Improved: The interface now has new colors and a new 'MailStore by OpenText' logo.
• New: Using IMAP for Microsoft 365 export profiles.
• New: Microsoft 365 Groups can be synchronized as MailStore users.
• New: A conversion tool for converting Microsoft 365 EWS profiles to Graph API and IMAP.
• Improved: Enhanced Graph API archiving and error handling.
• Improved: Third-party libraries have been updated.

MailStore Server 26.1

14/01/2026

• Deprecated: External Microsoft SQL and PostgreSQL-based archive storages are no longer available and will be removed in a future MailStore version.
• New: Microsoft 365 mailbox archiving profiles now use Graph API. Please ensure that your application is registered in Entra ID according to our instructions; especially, the Mail.ReadWrite permission is now required. This applies only to new profiles!

MailStore Server 25.4

01/10/2025

• New: Official support for Microsoft Exchange Server SE.
• New: Profile export for MailStore Cloud.
• New: Administrators can search for messages by specific message ID.
• New: Audit log entries can be exported and deleted.
• New: Journal and multidrop archiving profiles can be configured to delete emails based on age.
• New: Management API allows setting folder privileges for all folders of a user (SetUserPrivilegesOnAllFolders).
• Improved: The MailStore Client prefers Kerberos when configured via GPO for Windows Authentication (Single-Sign-on).
• Improved: A job is created to keep the permissions of a controller up-to-date.
• Improved: Third-party libraries have been updated.

MailStore Server 25.3.1

23/07/2025

• Fixed: Plain text messages are not displayed in web access.
• Fixed: PostgreSQL-based archive storages cannot be loaded.

MailStore Server 25.3

02/07/2025

• Note: Support for Windows Live Mail email client has been removed.
• New: New SMTP connection type with OAuth2 authentication support for sending emails via Microsoft 365.
• Improved: Enhanced indexing of digital invoice formats such as ZUGFeRD or XRechnung.
• Improved: The validity period of new certificates for Microsoft 365 Entra ID integration has been extended to 3750 days.
• Fixed: Emails restored via web access cannot be replied to.
• Fixed: Sometimes the Let's Encrypt installation cannot be completed or certificate renewal fails.
• Fixed: Archive profiles for Microsoft 365 daily mailboxes that do not archive filter out daily reports and NDRs.
• Improved: Third-party libraries have been updated.

MailStore Server 25.2

02/04/2025

• New: New Outlook.com archiving profile with OAuth support, including all email domain names such as outlook.com, live.com, hotmail.com, and msn.com.
• New: New NoSpamProxy archiving profile.
• Improved: Failed login attempts now include more detailed information in audit log entries.
• Fixed: Newly added archive storages do not open completely if a password is required.
• Improved: Third-party libraries have been updated.

MailStore Server 25.1

15/01/2025

• New: Official support for Microsoft Windows Server 2025.
• New: Outlook Add-in and Outlook Application now support Microsoft Outlook 2024.
• Improved: Support for Firebird 3 and 2.5 has been removed due to its dependency on older Microsoft C++ runtime libraries.
• Improved: Third-party libraries have been updated.

MailStore Server 24.4

10/10/2024

• New: New Outlook Application allows archiving and access from Microsoft 365 through the new Outlook and Web within Outlook. It provides functionality for integrated web access in Outlook.
• New: Support for archiving messages with binary content from MailStore Gateway 24.4 or newer versions.
• Improved: Installer warns users if they are trying to downgrade MailStore Server to an older version.

MailStore Server 24.3

03/07/2024

• New: The search function now supports searching for alternative terms in a list similar to the OR operation.
• Fixed: An old third-party library has been replaced with built-in functionality.

MailStore Server 24.2.2

07/05/2024

• Improved: To improve the stability of PDF indexing, text extraction from PDF attachments has been moved to a separate process.
• Fixed: Users who are synchronized from Active Directory and enable Multi-Factor Authentication (MFA) in MailStore cannot log in using Windows authentication.

MailStore Server 24.2.1

25/04/2024

• Note: When upgrading from version 24.2.0, archive storages need to be upgraded to recreate missing recovery records. Please read the upgrade announcements carefully for more information about the upgrade process.
• Fixed: Recovery records are not written when an archive storage needs to be upgraded.

MailStore Server 24.2

10/04/2024

• Note: The internal database infrastructure has been updated. Please read the upgrade announcements carefully for more information about the upgrade process.
• Note: Following Microsoft's product renaming, the name "Azure AD" has been changed to "Microsoft Entra ID".
• New: User logins can be secured with multi-factor authentication without using OpenID Connect.
• New: User logins can be restricted to specific clients.
• New: The plain text copy of an IRM protected message is archived from Microsoft 365 Daily Reports.
• New: Management API can be used to set allowed clients for a user (SetUserLoginPrivileges).
• Improved: The Management API command for creating users can be used to set allowed clients (CreateUser).
• Improved: The default list of allowed clients for synchronized users can be configured.
• Improved: Multi-Factor Authentication (MFA) can be enabled for synchronized users.
• Improved: Web Access: Major update of all basic web framework components.
• Improved: The client prevents renaming archives with uppercase letters.
• Fixed: Administrators who authenticate using OpenID Connect cannot change compliance settings that require a password approval.
• Fixed: The automatic exclusion of folders in Exchange and Microsoft 365 profiles cannot be re-enabled.
• Fixed: Various minor bug fixes and improvements.

MailStore Server 23.4

13/12/2023

• Note: Support for Windows Server 2012 and Windows Server 2012 R2 has been removed.
• Note: Support for Exchange 2003 and Exchange 2007 without service packs has been removed.
• New: Microsoft 365 daily reports can be filtered to extract undelivered reports.
• New: Flagged emails and emails marked for follow-up can be deleted from the source mailbox.
• New: Emails older than a specific date or date range can be excluded from archiving.
• New: Management API can be used to monitor worker result details (GetWorkerResultReport).
• New: Management API can be used to set the service certificate (SetServiceCertificate).
• New: Management API can be used to upgrade all archive stores in bulk (UpgradeStores).
• Improved: The user property used as the authorization identity in IMAP Main Password archiving profiles can be configured.
• Improved: Automatic discovery for Microsoft 365 Shared Folders archiving has been enhanced.
• Improved: Third-party libraries have been updated.
• Fixed: When configuring the Quick Access Toolbar, some Outlook versions show missing button descriptions.
• Fixed: Sending information emails about MailStore updates fails for all recipients except the first one.

MailStore Server 23.3.1

05/10/2023

• Improved: Updated PDFium third-party library to improve the stability of PDF indexing.

MailStore Server 23.3

20/09/2023

• New: Microsoft 365 archive mailbox can be archived.
• New: Microsoft Exchange Server archive mailbox can be archived.
• New: Retention policies now support using the message date as a reference date.
• New: Users who choose to save their credentials are automatically logged in.
• Improved: Updated third-party libraries on all web clients.
• Improved: Updated Docnet and PDFium third-party libraries to improve the stability of PDF indexing.
• Fixed: Directory synchronization with Kerio Connect fails when using TLS 1.3.
• Fixed: Directory synchronization with IceWarp Server fails when using TLS 1.3.
• Fixed: IMAP protocol can be selected for Microsoft Exchange Shared Folder archiving.

MailStore Server 23.2

21/06/2023

• Note: The Outlook Add-in needs to be updated to support Multi-Factor Authentication.
• New: Login credentials for users with integrated authentication can be secured using Multi-Factor Authentication.
• New: Users with integrated authentication can manage application passwords for MFA-inactive clients.
• New: When creating scheduled tasks for client-side archiving profiles, users must enter a password.
• New: Management API now has methods for initializing MFA (InitializeMFA), disabling MFA (DisableMFA), and deleting application passwords (DeleteAppPasswords).
• New: Management API can be used to monitor Microsoft 36 healthcare credentials (GetCredentials).
• New: A warning is shown when renaming an archive, and potential side effects are expected.
• Improved: The MailStore logo now displays the "by opentext" suffix.
• Improved: A temporary solution for Microsoft 365 shared folder archiving may not work occasionally due to a behavior in Microsoft 365.
• Fixed: Archiving of Microsoft 365 mailbox fails with "No key set" error.
• Fixed: User credentials are cached for too long when using LDAP General.
• Fixed: Copyright year needs to be updated to 2023.
• Fixed: Various minor bug fixes and improvements.

MailStore Server 23.1.2

29/03/2023

• Note: Let's Encrypt announced that they will permanently change their production request flow on April 24, 2023. After this date, previous versions of MailStore Server will not be able to successfully request certificates from Let's Encrypt.
• Fixed: Let's Encrypt installation fails due to an incompatible request flow.

MailStore Server 23.1

22/03/2023

• Note: Support for Windows 7, Windows 8.1, Windows Server 2008 R2, and Windows Small Business Server 2011 has been removed.
• New: Retention policies now support including or excluding specific archives.
• New: 21Vianet profiles run by Microsoft 365 for archiving and exporting emails using modern OAuth authentication as required by Microsoft. Due to technical and organizational reasons, please note that these profiles can only be used by MailStore administrators.
• New: Directory Services: New profile for Microsoft 365 using modern OAuth authentication to synchronize users via Microsoft Graph API and allow synchronized users to authenticate directly with Microsoft using OpenID Connect.
• Improved: It is now possible to delete multiple archives at once in the client.
• Improved: Help displayed for Management API within the client has been improved.
• Fixed: Various minor bug fixes and improvements.

MailStore Server 22.4

07/12/2022

• Improved: Resource management has been improved.

MailStore Server 22.3

21/09/2022

• New: Outlook Add-in now supports Microsoft Outlook 2021.
• New: Profiles can be set to run automatically on the server side and can be changed via Management API.
• New: Failed login attempts now help prevent brute force attacks by slowing down the login process.
• Improved: Login flow in Outlook Add-in has been improved.

MailStore Server 22.2.2

03/08/2022

• Improved: Installer now informs users about potential reboots due to Microsoft .NET Framework 4.8 installation.
• Fixed: Some users cannot access the audit log page.

MailStore Server 22.2.1

30/06/2022

• Fixed: Cannot log in using OpenID Connect.

MailStore Server 22.2

29/06/2022

• New: Both Windows 11 and Windows Server 2022 are now supported operating systems.
• New: TLS 1.3 is now supported for both outgoing and incoming connections on operating systems that fully support this TLS version.
• Improved: The underlying framework has been updated to .NET Framework 4.8.
• Improved: Third-party libraries have been updated to fix several minor issues related to archiving, displaying, and exporting emails.
• Improved: The internal database infrastructure has been updated.
• Improved: Client components for all used databases have been updated.
• Improved: The path structure for new MailStore Client and Outlook Add-in installations is now consistent with other MailStore products.
• Fixed: When using the signed export feature to export messages as MSG files, the signature gets corrupted.
• Fixed: Under heavy load, archiving may get stuck and never complete, which can also prevent other functions from operating properly.

MailStore Server 22.1.1

04/05/2022

• Fixed: Under certain conditions, a Microsoft 365 behavior prevents successful archiving of shared folders.

MailStore Server 22.1

23/03/2022

• Note: This version's version number follows the newly standardized MailStore version numbers that reflect the quarter in which the product was released.
• New: The status report's subject line now includes an action call for the administrator.
• Improved: Profile settings used during archiving and exporting are now validated.
• Improved: After installing a new license, the MailStore client no longer needs to be restarted.
• Improved: Input validation for file and folder paths has been improved.
• Improved: Input validation for archive storage auto-creation configuration has been improved.
• Fixed: During message re-indexing, the index may be marked as corrupt.
• Fixed: Binary encoded attachments may change during archiving under certain conditions.

MailStore Server 13.2.1

08/12/2021

• Note: Due to a change in PDF parsing, search behavior for PDF attachments may differ between previously archived and newly archived messages.
• Fixed: Some PDFs may cause the service to crash when being indexed.
• Fixed: Users can find messages by searching in the BCC field.
• Fixed: Messages sent by users contain Exchange BCC headers.

MailStore Server 13.2

29/09/2021

• Note: Due to a change in PDF parsing, search behavior for PDF attachments may differ between previously archived and newly archived messages.
• New: Integrated support for indexing PDF attachments has been added, removing dependency on Adobe PDF IFilter.
• New: Archive storages are now automatically created for optimal performance.
• New: API-accessible configuration for automatic archive storage creation.
• Improved: Telemetry collection performance has been improved.
• Improved: Performance of search result caching has been improved.
• Improved: Performance of reading recovery record files has been improved.
• Improved: Performance of re-creating search indexes has been improved.
• Improved: Web Access: Search performance has been improved for various scenarios.
• Improved: Client: Performance and user experience of the archive page have been improved.

MailStore Server 13.1

21/04/2021

• Note: Following Google's major product renaming for business products, the name G Suite has been replaced by Google Workspace throughout the software.
• New: If a license is changed, for example, renewed or extended, it can be automatically updated in the background (within approximately one day).
• New: Management API can now be used to retrieve license information.
• New: AD FS OpenID Connect support has been added when using the "Active Directory" directory service type.
• New: AD FS OpenID Connect support has been added when using the "LDAP General" directory service type.
• New: Administrators are now notified in the dashboard and status report when certificates used as credentials are about to expire or have expired.
• Improved: Significant performance improvement when moving messages within the same archive.
• Improved: Customer: When opening emails in a mail client, Thunderbird profile names are now displayed for all profiles.
• Fixed: Folder names with multi-byte Unicode characters are stored incorrectly.
• Fixed: Client: The x64 version of Thunderbird is not correctly detected.
• Fixed: Client: The client does not check for certificate revocation.
• Fixed: Client: Temporary export to Microsoft 365 or Exchange Server fails when using automatic detection.
• Fixed: Outlook Add-in: After removing the add-in, it cannot be reloaded in the same Outlook session.
• Fixed: