Changing the appliance hostname is not a painless operation, as you might lose emails. In this guide is explained how to perform a safe hostname changing.
Requirements
- Full access to your DNS administration panel
- Full access to the network nameserver for PTR record management
- Admin rights on the ESG
Create the record
First of all you need to login to your DNS management panel and create the new A record with the new hostname.
Change the PTR record
The next operation to perform is to change the PTR record on the nameserver where the network zone file is.
Note: the PTR worldwide propagation can take up to 72 hours.
Change the hostname on the appliance
Now you can change the MTA hostname on the appliance from the Networking page in the Network Settings tab.
Dealing with TLS certificates
TLS certificates depends on the appliance hostname, so you need to regenerate them from the TLS Certificates page by clicking on the New button from the table toolbar and applying them to both Web Interface and MTA.
Change the MX records
We are now ready to switch the email flow to the new hostname. From the DNS administration panel of your domain(s) change the MX records typing the new hostname.
Cleanup
The email flow should be switched now. To complete the procedure, you need to remove the old hostname (the A record) from your DNS administration panel.