We are using Microsoft Exchange Server 2003 SP2 and for the past 6 months we have been unable to receive email from people using Lotus Notes.
The users trying to send us email work for very large companies so I'm sure their email servers are tied down pretty tight. Here's the problem - When we send email via our MS Exchange Server 2003 to people using Lotus Notes, the message goes through and is received just fine. When the Lotus Notes user replys to the email, they get a timed-out NDR after X minutes.
Here's one of the NDRs the Lotus Notes user has received:
The e-mail system was unable to deliver the message, but did not report a specific reason. Check the address and try again. If it still fails, contact your system administrator.
< mlnyc904er.ml.com #4.0.0 X-Postfix; conversation with pcescorpserver.pcescorp.com[184.108.40.206] timed out while sending RCPT TO>
Does anyone know what needs to be done, on either side, to get these emails to stop timing out and go through? I've discussed this issue with the people who host our DNS and they told me there's nothing else they can do. We've added a SPF record, tried correcting any issues reported in DNSSTUFF.com.