The transition period and wrapping up

Module 4: Moving email · Reading time: 10 minutes

Learning objective: After this lesson, you can get through the days after the MX switch without losing mail, switch over all devices and settings neatly, and check and close off the email move.

Key concepts: transition period, cache, delta copy, test email, switching devices, removing the old account, throttling, shared mailbox, forwarding, autoresponder, archive export, cancelling

Why there is a transition period

After the MX switch (lesson 4.3), not all mail goes to the new server straight away. Servers that still have the old MX record in their memory (cache) will keep sending to the old provider for a while. How long that lasts depends on the TTL: with a TTL of 300 seconds it's a matter of minutes, with a TTL of a day it's a day. On top of that, some servers retry delivering a message that failed earlier, using the address they knew at the time.

The result: for a few days, mail arrives in two places. That's not a problem, as long as you're aware of it and don't close the old mailbox too soon.

Think of it as two letterboxes side by side. The new one is already hanging there, the address on the door has changed, but the postman who's still working from his old list drops the letter in the old box. So for a week, you check both. Then you seal up the old one and empty it one last time.

Day 1: the second copy and a first check

The day after the switch, run the migration of all mailboxes again. Messages that have already been copied are skipped; only the mail that still arrived at the old provider gets added.

Then check with test emails:

1. Receiving. From another address, for example a personal address on your phone over mobile internet, send an email to every important address: info@, bestellingen@ and a few personal addresses. Does it arrive in the new mailbox?
2. Sending. From the new mailbox, send an email to an address at Gmail and at Outlook.com. Does it arrive, and not in spam? Check the headers (in Gmail: Show original). You'll see spf=pass, dkim=pass and dmarc=pass if everything is set up correctly.
3. Forms. Fill in the contact form on your website and check whether the notification arrives.

If sending doesn't work or mail lands in spam, check SPF and DKIM first (lesson 4.3).

Switching over devices and programs

Every phone, laptop and tablet needs to move to the new server. Don't do this by changing the server name in the old account, but like this:

1. Add the mailbox at the new provider as a new account, with IMAP and the server name and ports of the new provider.
2. Check that the mail is there (the copy).
3. Remove the old account from the device.

That last step matters more than it seems. A forgotten old account keeps trying to log in in the background. With the old provider, that's harmless as long as the subscription is still running, but if the old mailbox has been closed, or the server name the old account uses now points to the new server, the device will try to log in with the wrong password every few minutes. Many mail servers then throttle or block the IP address, and suddenly the whole office can't send mail at all.

At Bakkerij De Korrel, everyone uses the Outlook app on their phone. The old Microsoft 365 accounts are removed; the new IMAP account is added. Two staff members use the built-in Mail app on the iPhone; the process there is the same.

Also think of devices without a screen: the scanner that emails PDFs to info@, the till, the webshop. These send via an SMTP server. If that still points to Microsoft's server, it will stop working as soon as the old account is gone.

What you need to set up again

From your list in lesson 4.1, take everything that didn't come across with the copy, and set it up at the new provider:

What to keep an eye on in the first few weeks

• The old mailbox. Check daily in the first week whether new mail is still coming in. If mail is still arriving after a few days, something hasn't been switched over: maybe a supplier is sending via an old forwarding address, or an MX record is still pointing somewhere else.
• DMARC reports. If you have a rua address, you'll get daily reports. If you see a server sending on your behalf that doesn't pass SPF or DKIM, you've forgotten a sender.
• Calendar invitations. These travel by email. If your calendar is already working with the new service (module 5), test whether an invitation arrives and whether accepting it is reported back to the organiser.

Wrapping up and cancelling

Once everything has worked well for a few weeks, you wrap up:

1. Run one last copy, in case anything still came in.
2. Make an archive export of the old mailboxes (PST or mbox, lesson 4.2) and keep it as a backup. Bear in mind retention obligations: business email containing tax-relevant information generally has to be kept for seven years in the Netherlands.
3. Clean up the DNS (lesson 4.3, step 5): old include, old DKIM, verification records, autodiscover.
4. Withdraw permissions: app passwords at Google, the approved migration tool in Microsoft.
5. Remove the domain from the old environment and cancel the licences. Don't cancel before everything has been checked; after cancelling, the old provider may delete your data after a certain period.
6. Ask for confirmation from the old provider that your data has been deleted, if you need this for your GDPR records (lesson 9.3).

In practice: what this looks like with a provider

The WebOké DirectAdmin manual sets out wrapping up in four steps: getting the MX set correctly (with a domain moving to WebOké, it's already set correctly from the start), copying again a day later, setting up devices as a new account and removing the old account, and only cancelling after a few weeks. You set up forwarding, autoresponders and holiday messages in DirectAdmin under E-mail Manager. The WebOké manual has an article called Mail isn't arriving: checking it yourself. With other providers, the parts are named differently, but the order is the same.

Summary

• For a few days after the switch, mail still arrives at the old location; keep the old mailbox open and copy again.
• Check with test emails: receiving, sending (spf, dkim and dmarc pass in the headers) and your website forms.
• Add the new mailbox as a new account on every device and remove the old one; forgotten old accounts cause throttling.
• Set up aliases, shared mailboxes, groups, rules, signatures and autoresponders again.
• Wrap up with one last copy, an archive export, cleaning up the DNS, withdrawing permissions, and only then cancelling.

Quiz

Exercise

Exercise A4.4: Is the switch complete? Do this check a few weeks after the switch. The program compares your mail records with what it saw from you earlier (in the exercises for lesson 4.1 or 4.3): the old provider must no longer be in the MX, the old include must be removed from the SPF record, and there must be a DMARC record.

Exercise E4.4: Test round and wrap-up list. Do the three test emails from this lesson and note down the results. Then work through the wrap-up list and tick off what's done.

Further reading

The steps in these articles apply to WebOké's services; with other providers it works in a similar way.

• DirectAdmin guide 10.4: After the move: MX Records and your devices
• DirectAdmin guide 8.1: All settings at a glance: servers, ports and security
• DirectAdmin guide 8.8: Sending or receiving doesn't work: how to fix it
• DirectAdmin guide 7.5: Forwarders: forwarding mail to another address
• WebOké manual 7.4: Mail not arriving: check it yourself
• WebOké manual 13.6: Am I blocked? Release your own IP address
• Receiving email while moving your domain name
• Dutch Tax Administration (Belastingdienst): record-keeping obligation (generally 7 years, in the Netherlands)