[Exim] DNS lookup or something?

Hi!

WHAT does exim do when there is a connection to the SMTP Port just after the
'Escape character is'-line?

Our leased line went down just a while ago, which somehow caused all
connections from local users to the server to time out. All machines are on
OUR side of the line that failed.

Is there any conf-option so that exim accepts incoming messages without
having an outbound connection?

Daniel