Mail servers

[Pete Walker]

I am having problems sending e-mails to one domain in particular.  They all
bounce back with the following error:

----- The following addresses had permanent fatal errors -----
<xyz at domain.co.uk>

  ----- Transcript of session follows -----
554 permanent problems with the remote server mail.domain.co.uk

When I contact their technical people I'm told that we are the only co.
having problems sending to them and it must be our DNS settings at fault.

I check their DNS settings and find that the mailserver doesn't respond
properly, so I try to ping it (from outside as well) and it doesn't respond.

So, I check mail settings for their domain and find that there are three
mail servers listed (2 in other domains) and the priority is set highest (5)
for the one which doesn't respond to a ping or traceroute.  The other two
servers are set with priorities of 10 and 20 respectively.

If anyone has any ideas as to what may be wrong I would love to hear from
them,

Kind regards,

Pete Walker
AD Software Solutions