When you change hosting servers for your domain name, including your website and email, it is necessary to update the domain's DNS zone accordingly so that it points to the new server(s).
While this step is relatively simple to perform, it does involve an intermediate latency period, known as propagation, during which the DNS records propagate to servers worldwide. The propagation time corresponds to the update time on the servers and can range from 5 minutes to 72 hours, depending on the TTL settings configured for your domain's DNS records.
During this propagation period, it is recommended, where possible, to continue retrieving emails from your old host for a few days after the migration to avoid losing some of your messages that might still be mistakenly routed to the old server.
Below you will find the steps to follow and the procedure to perform your email migration without interruption:
Step 1. Update the TTLs
On your zone file, lower the TTL to 300 seconds.
Step 2. Create your email addresses with your new hosting provider
Create your email accounts on your new hosting space, and use the same passwords if possible to facilitate management.
Step 3. Back up your emails
Go to your webmail and/or your email client (Outlook, Thunderbird, Apple Mail… or other) and create an archive of your email account to save all your emails to keep locally on your computer.
Step 4. Modify the DNS zone file
Update your zone file with the IP address of your new mail server.
Step 5. Point it to the new mail server
In your email client (Outlook, Thunderbird, Mail… or other), modify the incoming and outgoing servers of your email accounts and enter the name of the server of your new hosting.
Step 6. Monitor the old account for a few days if possible.
During this transition period, you will ideally have two email accounts for the same email address: your old email account with your previous hosting provider, accessible through your old webmail (as long as it remains active, usually for a few days), and the other on the new server configured in your email client. Retrieve or forward any messages that may still arrive in your old inbox. After a short period of about a week, you can then delete the old account.
Follow the same procedure for your website:
TTL update: lower the TTL to 300 seconds
Back up your website
Export your databases
Import your databases onto your new server
Migrate your site and reinstall all data on your new server
Modify the DNS records to point them to the new server
Testing for proper operation