mailserver name change

[Andee63]

I know this is proberbly easy

How do you change the name of your mailserver?. My mailserver has the name mail1.olddomainname.co.uk which it reports in the mail headers for domains using my server. I now need to change it to mail1.newdomainname.co.uk.

Would I also need to renew the server certificates?

Thanks in advance

[topdog]

You will need to change the hostname, what distro/mail server are you running and Yes if your certificates were generated for the old name then you need to change them