'possible delivery' - what is it mean?

a user told me that he sent email to couple of external email address but they never received his email message. no bounce back were received by him either. i checked our mail server transmission log and found that messages were sent out but ended with the following message

Message 12345567 to abc@xyz.com received remote SMTP response 'possible delivery'.  

what is "possible delivery" mean?
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Most probably there is a Ironport device within message flow which features "Possible Delivery".

If a message delivery times out before recipient host ackknowledges receipt of message body stream, Ironport can be set up to deem the message as "possible delivery", but still completed successfully.

Ironport's recommended setting is having this feature turned on, however, IMHO this violates RFC2821, since recipient has not yet taken over responsibility for the mail message, but Ironport claims to have transferred the message successfully with a 250 return code.


Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
qsecofr8Author Commented:
so this message isn't returned from the remote server ? instead it is generated from our ironport device?
yes. my office use ironport
yes it is.
qsecofr8Author Commented:
thank you
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Email Protocols

From novice to tech pro — start learning today.