Comparison
MailStore is solid software — but it's software: you install it on a Windows server and you keep that server running. mailvault365 is a service built only for Microsoft 365. Connect your tenant, and archiving runs on its own.
Software you buy, install on your own Windows server, and operate yourself — archiving profiles, updates, backups, and storage planning included. Supports many mail sources beyond Microsoft 365.
A service built only for Microsoft 365. Sign in, connect your tenant, and every mailbox is archived automatically — nothing to install, nothing to update, no server to look after.
The honest version: these are two different approaches, not a better and a worse product. One is self-hosted software with broad source support; the other is a managed service focused on one thing.
| mailvault365 | MailStore Server | |
|---|---|---|
| Setup | Connect your Microsoft 365 tenant — about 5 minutes | Install on a Windows server, then configure archiving profiles per source |
| Runs on | Our infrastructure, hosted in Europe | Your own Windows server (or a hosted one you manage) |
| Maintenance | None — updates, backups and storage are our job | Yours — OS and software updates, backups, storage planning |
| Mail sources | Microsoft 365 only, including shared mailboxes | Many: Exchange, Microsoft 365, IMAP/POP3 accounts, PST files and more |
| Search | Full-text search across every mailbox you have access to, saved searches | Full-text search in the archive |
| Access model | Everyone sees only their own mailbox by default; extra access is granted per user and every cross-mailbox access is logged | Configured by your administrator |
| Leaver mailboxes | The archive stays, searchable, even after the Microsoft 365 user is deleted | Archived mail stays on your server |
| Storage | 20 GB per mailbox, pooled across your account | Limited by your server's disk |
| Pricing model | $4 per mailbox / month, cancel anytime, no setup fees | Per-user licence plus annual update & support, self-hosting costs on top |
| Data export | Standard .eml files — download any message, full export on request | Export via built-in tools |
We'd rather you pick the right tool than sign up for the wrong one. Choose MailStore if:
Yes — contact us and we'll take care of the switch together. Everything still in your Microsoft 365 mailboxes is archived automatically the moment you connect; for history that only lives in your MailStore archive, we'll work out the right migration path with you.
Archived emails cannot be changed or individually deleted by anyone — including admins. That supports the requirements for unalterable retention; which retention periods apply to you depends on your country and the document type.
No. We connect with read-only permissions via Microsoft Graph. We never write to, delete, or modify a mailbox.
Their archive stays, fully searchable, even after the Microsoft 365 account is deleted. You keep paying for the mailbox only as long as you keep its archive.
No. Every message is stored as a standard .eml file — never a proprietary format. Download individual messages anytime; on cancellation we arrange a complete export.
Connect your Microsoft 365 tenant and watch the archive fill up. 14 days free, no credit card, no sales call — then $4 per mailbox per month.