What to Do When Your Email App Shuts Down

Email clients get acquired and sunset on a regular schedule. Postbox was discontinued, Windows Mail was retired, and Notion Mail is shutting down in September 2026 — and there will be more. So it is worth knowing exactly what to do when your email app shuts down before it happens to one you rely on.

The good news is that a shutdown is rarely the disaster it feels like. In most cases your actual messages are never at risk. What is at risk is the layer the app built on top of them — and that layer usually has a deletion date that lands before the app itself goes dark.

This guide is the durable playbook: work out where your mail physically lives, extract what only exists inside the app, and pick a replacement on whether it will still be here in two years rather than on its feature list. Every date below is stamped; re-check it against the vendor's own page before you act.

First: is your mail on the server or only in the app?#

This one question decides everything else. An email app is one of two things. It either reads a mailbox you already own — over IMAP, Exchange, or a provider API like Gmail's — or it hosts your mail itself and is the only place that copy exists.

If the app only synced a mailbox you own, the shutdown costs you settings and habits, not messages. Disconnect the app, open your provider's webmail, and every email is still there. Point a new client at the same mailbox and you are done that afternoon.

If the app hosted your mail — a privacy service like the former Skiff, or any provider that gave you an @its-own-domain address — a shutdown is a real migration. You must export the archive and set up forwarding before the cutoff, or mail sent to that address simply stops arriving.

Here is what typically survives a shutdown and what does not.

The pre-migration checklist#

Before you touch a single setting, pin down the two dates that matter and the short list of things only the app holds. Most of this takes under fifteen minutes.

• Find the shutdown date and the deletion date — they are usually different. Notion Mail's inbox retires 22 September 2026, but drafts, scheduled sends, snippets and auto-label rules are permanently deleted if not exported by 21 September 2026 (Notion Help). The deletion date is your real deadline.
• Confirm where your mail lives. Disconnect the app or open your provider's webmail; if the messages are there, they are safe.
• List everything that is app-only: signatures, templates, rules, snippets, scheduled sends, snoozes, saved searches, AI summaries. This is what disappears.
• Check who holds the login. If the app used an OAuth grant from Google or Microsoft, you will revoke it later. If it hosts a separate mailbox and address, plan forwarding now.
• Pick your replacement early, not on the last day, so you can run both side by side.

Steps: get everything out before the deadline#

Do this while the old app still works. An export you have never run is a promise, not a backup.

1. 1

   Run the built-in export first

   Look in Settings for an export or download option and run it now. Notion Mail, for example, lets you save drafts, scheduled sends, snippets and auto-label rules before the shutdown. Do it early — large mailboxes take time and download links often expire.

2. 2

   Save the app-only layer by hand

   Copy your signatures, templates and the wording of any rules into a plain-text or document file. These almost never export in a format another client can read, so a manual copy is the reliable route.

3. 3

   Make sure the messages themselves are safe

   If the app hosted your mail, export it as MBOX or EML — formats other clients import. If it only synced a mailbox you own, confirm the mail is in your provider's webmail and skip this step.

4. 4

   Set up forwarding if you are losing an address

   For a hosted address, turn on forwarding to your new address before the cutoff, so replies to old threads still reach you after the app is gone.

5. 5

   Open every exported file

   Check the messages are readable and that your drafts, rules and snippets are actually in there. What is missing is the finding you need before the deadline, not after it.

What breaks when the app goes dark#

Even with a clean export, some things stop working the moment the app is retired. Here is what you will notice and what to do instead.

Your safety net (there is no undo on a shutdown)#

A shutdown only moves one way — you cannot roll back to an app that no longer exists. So the rollback plan is really a safety net you keep until the new setup is proven.

Keep the old app installed and do not delete your account with the vendor until the new client has synced fully and you have confirmed nothing is missing. Keep the export archive somewhere permanent, not inside the app you are leaving. And keep any forwarding running for a few months, because people email old addresses long after you have moved.

Only once the new client is verified should you revoke access and remove the old app.

Switching without downtime#

You do not have to wait for the app to die to move. If it only synced a mailbox you own, the cleanest approach is to run the old and new clients side by side.

• Connect your new client to the same Gmail, Outlook or IMAP mailbox while the old app is still running. Both show the same server-side mail, so there is no gap and nothing to import.
• Rebuild your rules and templates in the new client over a few days, checking each one against the old app before it shuts down.
• For a hosted mailbox with its own address, forwarding is what buys you time. Skiff, the privacy mail host Notion acquired in February 2024 (TechCrunch), gave departing users a transition window with export and automatic forwarding so mail to old addresses was not lost during the move.

Choosing a replacement that won't shut down next#

Once the fire is out, pick the next tool on continuity, not just features. Two apps with identical features can carry completely different risk depending on where they keep your mail.

The single best protection is a client that reads a mailbox you own rather than hosting it — Gmail, Microsoft 365, iCloud, Fastmail or any IMAP host. Then a future shutdown can only cost you settings, never messages. After that, look for a self-serve export you can run yourself, a clear list of what is app-only, and whether email is the company's main business or a side bet that could be cut.

Even features inside healthy apps get retired: Google is winding down Gmailify and POP "Check mail from other accounts", with no new setups after the first quarter of 2026 and existing connections continuing until January 2027 (Gmail Help). Longevity is never guaranteed — so buy the tool whose worst case you can live with.

We build AI Emaily, so treat this as the interested party's view. It connects to the Gmail, Outlook, iCloud, Fastmail or IMAP mailbox you already own and never hosts your mail, which means that if AI Emaily itself shut down, your messages would still be with your provider — you would connect another client and lose only the app-only layer. That layer exports to a self-serve file, and every send goes through approve-before-send with undo and an audit trail. The honest limits: the desktop app is an Electron build for macOS (Apple Silicon) and Windows with no Linux build, Android is a PWA, and offline is partial. It is a 7-day free trial rather than a free-forever plan — see current plans at aiemaily.com/pricing, or the overview at aiemaily.com.