MailStore Server

What is included in MailStore Server?

Central Archiving – Stores 1:1 copies of all company email.
Broad Sources – Archives Exchange, Microsoft 365, Google Workspace, IMAP.
Built-in Storage – No external database server needed for operation.
Compliance Tools – Retention policies, legal hold, audit logging included.
Core Capacity – One installation handles up to 2,000 users.
Important – No native Mac or mobile client app.

What are the main benefits of MailStore Server?

MailStore Server is on-premise email archiving software for small and medium-sized businesses that keeps a central, tamper-proof copy of every message. It offloads the mail server while keeping each email searchable and restorable for years.

Mailbox Offloading – Frees Exchange storage using rule-based source deletion.
Fast Retrieval – Full-text search across emails and attachments.
Storage Savings – De-duplication and compression cut storage roughly 70%.
Outlook Access – Archive opens directly inside the Outlook add-in.
Compliance Ready – Meets GDPR and GoBD email retention requirements.
Quick Restore – One-click recovery without touching server backups.

Data loss is expensive: How backups help you avoid outages
For more background on backup planning, read our guide:

What does MailStore Server do?

It is on-premise email archiving software that builds a central 1:1 copy of every inbound and outbound message. Administrators define archiving profiles per source — Exchange, Microsoft 365 via the Graph API, Google Workspace, IMAP/POP3, or PST files — and can automatically remove archived mail from the source to shrink mailboxes. The archive stays tamper-proof and fully searchable for years. Individual messages can be restored to the original mailbox or exported in a single step.

Who is MailStore Server best suited for?

It fits small and medium-sized businesses that must retain email permanently for compliance, eDiscovery, or recovery of messages from former employees. A single installation scales to about 2,000 users, covering most SMB and mid-market sites without a multi-server build. It is most valuable where bloated mailboxes and fragile PST files need to be consolidated into one indexed archive instead of restoring from backup for every email request. Larger hosts that resell archiving as a managed service use the separate Service Provider Edition instead.

Which email systems and file types can it archive?

MailStore Server archives from Microsoft Exchange, Microsoft 365, Google Workspace, and any IMAP- or POP3-compatible mailbox, plus public folders, email clients, and PST files. Microsoft 365 archiving now runs through the Microsoft Graph API, which matters because Microsoft is ending Exchange Web Services (EWS) for Exchange Online on October 1, 2026. Journaling can capture every message the moment it is sent or received, while one-off profiles pull in historical PST data. Attachments are indexed for full-text search alongside the message body.

Does MailStore Server include native Mac and mobile apps?

No. MailStore provides a Windows Client application and an Outlook add-in for desktop users, but Mac and mobile users reach the archive only through the browser-based MailStore Web Access. There is no dedicated macOS client and no native iOS or Android app, so mixed-platform teams should plan around web access for non-Windows staff. The server service itself is Windows-only, and any installation with more than 25 users requires a Windows Server operating system because of client-OS connection limits. This is the main platform constraint to confirm before buying.

How does it differ from MailStore Home and the Service Provider Edition?

MailStore Home is free but licensed only for private, personal use, so businesses cannot run it legally. MailStore Server is the commercial on-premise edition for a single organization and scales to roughly 2,000 users per installation. The Service Provider Edition (SPE) is multi-tenant, managed through a web console or API, and built for MSPs and hosters serving many separate customers across multiple servers. For one company archiving its own mail, MailStore Server is the correct edition rather than Home or SPE.

What should I check before choosing MailStore Server?

Confirm you can dedicate a Windows machine, and a Windows Server OS if you have more than 25 users, since the archiving service does not run on macOS or Linux. Make sure Microsoft 365 archiving uses the Graph API, because EWS-based profiles stop working when Microsoft retires EWS for Exchange Online in October 2026. Note that MailStore is removing support for external Microsoft SQL Server and PostgreSQL databases by the end of 2026, so plan on the built-in storage engine. Finally, set up a backup of the archive store itself, as it becomes the system of record once mail is deleted from the source.

Frequently asked questions about MailStore Server

Does MailStore Server need an external database or web server?

No. It ships with an integrated storage engine, so no Microsoft SQL Server or PostgreSQL is required, and it runs its own HTTP server for MailStore Web Access without IIS or Apache. This keeps the deployment self-contained on a single Windows host.

Does email archiving replace a backup?

No. A backup is a short-term recovery copy of a live system, while the MailStore archive is a long-term, tamper-proof record of mail content. Because messages can be deleted from the mail server once archived, you should still back up the archive store separately using the integrated backup feature or third-party software.