I have reviewed through the previous posts concerning Semaphore Timeout Period Has Expired, and applied the suggested solutions. To no avail.
I have an SBS 2003 R2 server which I am able to send email to another SBS server in another domain. When there is an attachment in the email, it will remain in the queue for 24 hours plus and return the following message to the user.
Sent: Thursday, October 04, 2007 11:39 PM
Subject: Delivery Status Notification (Delay)
This is an automatically generated Delivery Status Notification.
THIS IS A WARNING MESSAGE ONLY.
YOU DO NOT NEED TO RESEND YOUR MESSAGE.
Delivery to the following recipients has been delayed.
In the queue the message displays Semaphore Timeout Period Has Expired.
I have Symantec Client Security 3.1, which is now uninstalled and the server has been rebooted. I have sucessfully ran smtpdiag and can send email without attachments.