Delivery Time Expire

My getting the following message after 24 hrs while sending emails to yahoo.com. Emails to all other domains are going properly.eporting-MTA: dns;abc.xyz.com.pk

Final-Recipient: rfc822;123@yahoo.com

Action: failed

Status: 5.0.0

Diagnostic-Code: X-Notes; Delivery time expired

Kindly help me in this regard.

Subject: Delivery Time Expire

Can anyone else from your company send to the same domain? To the same recipient? Try sending a test message with a trace on it and see how far it gets and what kind of messages you get back from that.

Subject: Delivery Time Expire

No one is able to send the email to yahoo.com. Trace message shows nothing. I think emails to yahoo are not forwording from my server.