[Pkg-exim4-users] SMTP Problems

[Robert Steinmetz AIA]

I have recently become aware of a problem sending mail to one of my 
customers, it seems some mail silently fails to be delivered. I have 
tried telneting into their smtp server and all connections fail with 
time outs.

Any idea how I can troubleshoot this issue? My customer is a very large 
company and seem disinclined to admit the problem is on their end.