Well, I tried doing a manual telnet connection to verify the address, and it
appears to have been caused by a missing alias file for the virtual domain...
How do I make exim ignore the fact that an alias file is missing if there
aren't any aliases for that domain rather than giving an 451 error message?
> > Diagnostic-Code: smtp;451 Temporary local problem - please
> try later
>
> this is an exim error message. you do have some kind of problem. what
> exactly is up to you to find in the logs ;) you probably want to
> grep 'T=.[^ ]* defer' /path/to/mainlog to find the cause.
