Jed,

Moving email server to a different provider/server is not very simple. Changing every user to point to the new server and migrating their emails takes long. Therefore, we recommend you do this gradually. Here are the steps:

• Install Xeams in front of Postfix and run it in Hybrid mode
• Do NOT create every user in Xeams yet. Instead, create users gradually. Since Xeams will be running in Hybrid mode, messages will go to both Xeams and Postfix until to decommission Postfix completely.
• Assume you're using Thunderbird for email client, archive emails from Postfix into Thunderbird so that if Postfix goes away, emails are saved to the local machine.
• Create one user in Xeams and point the user's Thunderbird now to the POP3/IMAP server in Xeams. New emails to this user's account will now be fetched from Xeams. Repeat this process gradually for every user.