The email is off when the domain is suspended, if you change the domain when it's suspended, there will be a file not found error for /etc/virtual/domain.com, then the email will become unuseable.
tested problem exists on 1.293 as well.
Just create a test domain in domain setup, suspend the domain then try to change the domain to something else there will be an error:
Unable to swap email: Error moving /etc/virtual/test1.com to /etc/virtual/test2.com : No such file or directory
Now I follow ... you're trying to change the domain name.
Since suspending a domain changes the name of the link (as the easy way to do the suspend), it's not there to change. You could of course easily enough log in through a shell and do:
Well, if it's me running into this problem I would ofcouse able to fix it. but some of my clients don't know what they are doing and sometimes run into this error and I have to correct it, so if possible I would like to see this fixed since it's not hard to fix.