Mail Client vs Mail Vault: A Mirror Forgets, a Vault Keeps
Every mail client you have ever used is a mirror. It shows you what is on the server, keeps a local cache for speed, and stays in sync. That is the whole design: whatever the server holds, the client reflects.
Which is exactly why a mirror forgets. When the server deletes a message, an expiry policy kicks in, or the account itself goes away, the reflection goes with it. A vault works differently. It is a copy that does not answer to the server: once a message is in your vault, nothing that happens upstream touches it. That is the whole idea behind MailVault: a full email client with a vault behind it. You read, search, thread, and reply the way you would in any client, and every message you keep is written to your own disk as a standard .eml file, readable by anything. When the provider deletes it, expires it, or asks you to pay for storage, your copy does not care.
The Core Difference
A mirror and a vault answer the same question ("where is my email?") very differently. A mirror's answer is always on the server, reflected here. Change the server, and the mirror changes with it. A vault's answer is on your disk, as a file. Change the server all you like; the file does not move.
Neither one is wrong. A mirror is what makes multi-device email work at all: the same inbox on your phone, your laptop, and the web, always agreeing. A vault is what makes email outlast the server, the account, and the provider. MailVault is both at once: a full mail client for the day-to-day, built with the vault behind it from the start, not bolted on afterward.
Feature Comparison
| Typical mail client (mirror) | MailVault (vault) | |
|---|---|---|
| Server deletes or expires a message | Disappears from your inbox too | Stays put: it is a file on your disk, not a reflection |
| Account or provider goes away | Everything synced through it goes with it | Unaffected: your archive is not a subscription |
| Storage format | Proprietary local cache, tied to that app | Standard Maildir + .eml (RFC 5322), readable by any client |
| Search when offline | Only whatever happens to be cached | Full search of everything archived, from a private local index |
| Backups | Not really its job | Scheduled backups to an external drive or folder (Premium) |
| Export | One message at a time, if at all | ZIP export of everything, or one thread as an image or self-contained page |
| Switching providers | Migration headache, mail tied to the account | Already yours: archive it before you ever close the old account |
| Day-to-day email | Yes | Yes: threads, search, compose, reply |
When a Mirror Is Fine
Most days, a mirror is exactly what you want, and you do not need anything else. If your provider's own retention keeps years of mail live, if storage has never been a problem, and if you are not worried about the account itself disappearing, the mirror is doing its job. Plenty of people never need a vault at all.
When You Need a Vault
A vault starts to matter once the mirror's assumption breaks, once the server no longer holds everything indefinitely:
- The server enforces deletion or expiry. Some providers age out old mail automatically, or a mailbox is capped and old messages have to go.
- You are closing or switching a provider. Archive everything from an account before you shut it down, not after.
- Storage costs are adding up. Move old mail off the server, reclaim the space, and stop paying to keep it there.
- You need mail to outlast a single provider. Compliance, retention, or simply not wanting years of correspondence to depend on one company staying in business.
- You want it searchable offline. A vault answers instantly with no connection required, straight from its own index.
If any of those sound familiar, the guide to keeping emails after server deletion walks through the mechanics in more detail.
Switching Is Not All or Nothing
Moving to MailVault does not mean giving anything up on day one. It connects to your account over IMAP the same way any other client does, so you can keep your old client running on your phone or another computer while you try MailVault here. An account can have more than one client attached to it at once, and adding MailVault does not break what is already running elsewhere.
The vault builds itself in the background from the moment you connect the account, whether MailVault ends up being the only client you use or one of several. When something disappears upstream, the copy already sitting in your vault does not.
Ready to Keep What Matters?
MailVault is free and works with any IMAP email account. Download it, connect your account, and start building your vault in minutes.
See all features, read the FAQ, or compare MailVault with Apple Mail, Thunderbird, and paying for more storage.