MailStore Alternatives: Seven Options, Sorted by Use Case

The right MailStore alternative depends on which MailStore you are replacing and why. MailStore Home is a free Windows archiver for private use. MailStore Server is a paid Windows archive for companies. This roundup sorts seven real options into four groups: personal use on a Mac or Linux, personal use on Windows, open-source archive servers, and the tools already built into Microsoft 365 and Google Workspace. We make MailVault, one of the seven, and we list its limits next to everyone else's. For a deeper look at one pair, read MailVault vs MailStore Home or MailStore Server alternatives.

The seven options at a glance

Last checked: October 2026, on each vendor's own site or repository. Prices and features change, so confirm before you buy or deploy.

For one person on a Mac or Linux

MailStore Home needs Windows 10 or 11, so Mac and Linux users have to look elsewhere. Our MailStore alternative for Mac guide goes into the Mac case in more depth.

1. MailVault

MailVault is a free email app for macOS, Windows and Linux that keeps a copy of the mail you choose in a local vault on your computer, as plain .eml files in Maildir-style folders. It connects to Gmail, Microsoft 365, Outlook.com and any IMAP account, imports MBOX files such as Google Takeout exports, and searches everything it holds with a local index, offline. Manual backups are free and unlimited. Archive and Delete from Server are free as separate steps, and the one-step Archive & Delete, which checks each copy before removing the server copy, is Premium.

Limits: no PST import, no Outlook or Thunderbird profile import, no shared archive for several users, and no retention policies or legal hold. Attachment search, scheduled backups and cleanup rules are Premium.

2. Mail Archiver X

Mail Archiver X from Moth Software is a paid Mac app that archives from Apple Mail, Outlook, Thunderbird, Postbox and IMAP accounts, including Gmail and iCloud. It keeps the archive in an internal database with a search index, can export to PDF and MBOX, and the archive can sit on an internal or external drive. The vendor lists network storage too, but its manual says the standard edition expects a local archive. A Pro edition with a server component adds access from several computers and users. The current version is 8.2.4.

Limits: Mac only, and the archive is a database rather than one file per message, so you export to get standard files out. The price is in the vendor's manual: $49.95 plus tax, with Pro from $150.

For one person on Windows

On Windows, MailStore Home itself is still free for private use. If you are leaving it anyway, or want a setup that also works on other systems, MailVault runs on Windows too, and there is a free do-it-yourself route.

3. Thunderbird with ImportExportTools NG

Thunderbird is a free mail client for Windows, macOS and Linux. Its Archive button moves messages into an archive folder, and you can point that folder at Local Folders on your computer, filed by year or month. The free ImportExportTools NG add-on exports messages as EML, HTML, PDF, CSV or plain text, exports folders as mbox, and imports mbox and EML files.

Limits: Thunderbird stores each folder as one mbox file by default; Maildir storage is opt-in per account, and Mozilla calls it experimental and says to know how to file bugs and restore your mail before turning it on. Archiving is manual, and once mail is in a local folder, the backup of that folder is your job. See MailVault vs Thunderbird for the details.

Open-source archive servers

These replace MailStore Server more than MailStore Home. All three are free to use, and all three need someone to install, update and back up a server.

4. Mail-Archiver

Mail-Archiver (a different product from Mail Archiver X) is a self-hosted web app under GPL-3 that runs in Docker next to a PostgreSQL database. It syncs IMAP accounts and Microsoft 365 through Microsoft Graph, connects personal Outlook.com accounts, imports MBOX and zipped EML, and exports the same formats. Several users can share it with per-account permissions. It can delete mail from the server after a period you set per account, and it keeps an access log of logins, searches and exports.

Limits: no HTTPS of its own, so it needs a reverse proxy, and its README lists no legal hold.

5. Piler

Piler is an open-source archive server under GPL-3. The free Open Source Edition takes mail over SMTP, ingests Office 365 and Google accounts, reads EML, Maildir and mailbox files, and includes archival and retention rules, legal hold, audit logs, deduplication, compression and message encryption. It signs users in through AD or LDAP, single sign-on and two-factor codes. The Enterprise Edition is paid, with published pricing tiers, and adds eDiscovery, multi-tenancy and optional paid support.

Limits: the free edition is for a single server with community support, and Enterprise pricing is by request only.

6. Open Archiver

Open Archiver is a self-hosted platform under AGPL-3, started with Docker Compose. It ingests Google Workspace, Microsoft 365, IMAP, PST files, zipped EML and MBOX, and indexes the text of messages and attachments such as PDF and DOCX. It stores emails as .eml files with deduplication, compression and encryption at rest, on local disk or S3-compatible storage, records a hash of each message at ingestion, and keeps an audit trail.

Limits: its README marks legal hold as still to come, and it asks for at least 4 GB of RAM in the default setup.

Enterprise: the archive your provider already has

7. Microsoft Purview or Google Vault

If the company's mail is in Microsoft 365, Microsoft Purview retention policies and labels keep copies of mailbox items after users delete them, and eDiscovery can search them. Check which Microsoft 365 plan includes the parts you need. If the mail is in Google Workspace, Google Vault handles retention rules, holds, search, export and an audit log of Vault activity, on editions that include it.

Limits: the copy stays in the same provider's cloud, so these are not an independent backup. Google says Vault is not a data archive and keeps nothing until you set rules. For a separate Windows-based archive with the same kind of controls, MailStore Server itself remains an option.

How to choose

1. Who is the archive for? One person's mail is a desktop job. Many people's mail, searched by someone else, is a server job.
2. Do you need retention rules, legal hold or an audit log? If yes, look at Piler, MailStore Server, or your provider's own tools. The desktop options here do not do this.
3. Where is your old mail? PST files point to MailStore Home or Open Archiver. MBOX files and IMAP accounts work with nearly everything here.
4. What format do you want to be left with? If you want plain files you can open in ten years without the tool, prefer one file per message, such as .eml.

Frequently asked questions

What to do next

Pick the group that matches your case and try one tool on a single mailbox before you move everything. If you are one person on a Mac, Windows or Linux and want your mail as plain files, download MailVault free and archive one old year first. Our IMAP backup tool checklist helps you test any of these tools the same way.