Thanks for your reply,
The exchange server was working properly from 5:56 pm till 11:23 am an there is no other attempts in the log. The sender and the receiver are located in the same exchange server.
I'm using Exchange 2010 and outlook 2007 as a client.
A user sent email at 5:56 pm to multiple internal and external recipients from outlook 2007 but the message has delivered next day at 11:23 am.
-At sender's side: the message in sent items folder in outlook and OWA indicates that it has...