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Switch from Runbox to Posteo: step by step

How to move your mail, contacts and address from Runbox to Posteo without losing anything. Most moves take an evening to set up, then a few weeks of forwarding.

Compare them side by side

Watch out for

  • Posteo doesn't let you use your own domain, so you can't take an address like you@yourname.co.uk with you.
  • Posteo's migration service works over IMAP only, not POP3.
  1. Before you start

    • Check where your address lives. If it ends in @runbox.com, it belongs to Runbox and stays there: you'll forward your mail and tell people your new address. If it's on your own domain, like you@yourname.co.uk, it comes with you: you'll change a few DNS settings.
    • Check the space you need. See how much mail you have in Runbox, and compare it with Posteo's plans (the cheapest is Posteo, €1 a month, with 4 GB).
    • Read the small print. Posteo's page covers exporting, cancelling and refunds under "Before you sign up".
  2. Open your Posteo account

    Sign up on Posteo's website (No, €1 a month from the start), and turn on two-step sign-in straight away. You'll find the link on Posteo's page: Posteo.

  3. Bring your mail across

    Use Posteo's importer. Posteo's free migration service copies up to three accounts, with their folders, from any provider that allows IMAP. Open Settings, then My account, then Posteo migration service. Posteo's guide ↗

    Your old mail stays where it is while it's copied, so nothing is lost if you need to start again.

  4. Move your contacts and calendar

    Export your contacts as a .vcf file and each calendar as an .ics file from Runbox, then import them into Posteo. Most providers have both options in their contacts and calendar settings. Posteo can copy your address book automatically from Gmail, iCloud, Microsoft, Yahoo, AOL, GMX and WEB.DE. Posteo's guide ↗

  5. Keep your @runbox.com address working

    1. Forward new mail. Look in Runbox's settings for automatic forwarding, and add your new address.
    2. Tell people. Send your new address to the people who matter, and add it to your email signature.
    3. Update your sign-ins. Change the email address on your bank, shopping, social and work accounts. A password manager's list of saved sign-ins is the quickest checklist.
    4. Keep the old account open for a while. Mail will keep arriving there for months. Sign in now and then so it isn't closed for not being used.
  6. Check everything arrived

    • Compare the number of emails in each folder on both sides.
    • Send a test email to your new address from another account, and reply to it.
    • Check that mail forwarded from Runbox is arriving, and isn't going to spam.
  7. Close Runbox, when you're ready

    Wait at least a month, until nothing new arrives there. On a free account you can leave it open with forwarding on instead. Before you close a paid account, download a last copy of your mail.

    • Cancelling: Cancel during the free trial, or simply don't renew when your subscription ends.
    • Refunds: No refund when a subscription ends. A refund for the rest of the period only if Runbox seriously breaks the agreement and doesn't put it right within 30 days.
    • Renewal: Doesn't renew by itself: you renew before it ends to keep your account.

    From Runbox's page: Runbox.

I checked the providers' help pages on 24 October 2026. Menus move, so if a step doesn't match what you see, tell me and I'll update it.

Moving to Posteo from somewhere else? Gmail to Posteo · Outlook.com to Posteo · iCloud Mail to Posteo · Proton Mail to Posteo · Fastmail to Posteo · Tuta to Posteo · All switching guides

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