How to migrate your business email to Fastmail from another provider

If you own your own domain, you can use it with Fastmail, setting up all the accounts and aliases you require. Transitioning onto Fastmail is painless and can involve no down time.

Initial mail configuration

  1. Add your domain to Fastmail, but keep the MX registration pointing at your old host.
  2. Add all your users' email addresses to Fastmail
  3. Add all your aliases to Fastmail.

At this point all your mail is still being delivered to your old provider, but you have the users ready on Fastmail. From here you can either choose to swap everyone at once, or slowly migrate one user at a time.

Migrate users and domain

There's two ways to migrate your user accounts and domain from your existing provider to Fastmail: all users at once, or one user at a time.

If you only have a few users, or you are able to complete the migration out of core business hours, then migrating all at once is an easier option.

If you have many users, or you wish to avoid any downtime, then migrating one user at a time is preferable.

Migrate all at once

Switch your name server / MX records to point to Fastmail. Depending on the TTL of the domain, after about an hour, new mail should be delivered to Fastmail and into your users' inboxes.

Then use our email import tool for each user, to copy email from your old provider to each user's Fastmail account. If they have mail on their desktop (downloaded via POP), they'll need to manually transfer those folders to Fastmail's servers if they want it to be backed up.

Pros: Less steps to complete migration.

Cons: During the MX changeover, mail will still be arriving at the old provider until the TTL expires and mail is now sent to Fastmail. Then the user needs to wait until the import is completed before they have access to their mail history from Fastmail. This delay can be mitigated if the migration takes place out of regular business hours.

Migrate one at a time

At your existing email provider, set the user's email account to forward all email to us via one of our forwarding tunnel addresses. This will ensure that any new email that arrives at your old provider will be forwarded to Fastmail.

Use the email import tool to copy email for that user from your old provider to the user's new Fastmail account. If they have mail on their desktop (downloaded via POP), they'll need to manually transfer those folders to Fastmail's servers if they want it to be backed up.

At this point, this user can use Fastmail to send and receive their email, even though your old provider is still active. When all users have been migrated this way, then you can switch your name server / MX records to point to us. The DNS TTL lag has no effect as any mail arriving at the old server is forwarded to Fastmail.

Pros: User experiences no delay: they have complete access to their old mail and new from Fastmail once the mail import is completed. You can check the status of each user individually.

Cons: An extra configuration step is required in setting up the forwarding tunnels for each user. This can be time consuming if there are many users, but fortunately they don't have to be all done at once.

Migrate contacts and calendar

Each user will want to also migrate their contacts and any calendar entries. Follow our personal migration guide on completing these steps. It also covers how to change settings on email clients and mobile devices, and how to use two-step verification (2FA) to keep accounts secure.

Forwarding Tunnel

The forwarding tunnel allows you to forward email from an existing service to an account with the same name at Fastmail. For example, if you have the account at an existing service, you can create an account with the same name at Fastmail then use one of our forwarding addresses to deliver mail to it, even though the MX records for your domain still point to your previous email host.

There are 2 encoding options you can use, because some providers are limited as to what characters and/or the domain length you can put in an email address to forward to. To forward email to the Fastmail account, you can use either of: