We run Exchange 2003 in a WIndows 2000 domain. Most of our clients
(including the problem user) use citrix, so the setup for individuals
has little variation on basics such as Outlook 2003. One user
continually has problems sending out and several times a day
(sometimes much more), she is prevented from sending emails with
the error:


The following recipient(s) could not be reached:


John Doe on 20/09/2007 10:01
No transport provider was available for delivery to this
recipient.


I looked up the 'no transport' issue on Microsoft KB, and nothing was
really applicable except I thought problem contacts, but then the
user
told me that the last four times she received these NDRS, all she had
done was replied to messages that had been sent to her. The user can
usually re send the messages successfully later on in the day.


One thing I should also mention is that she is a remote user BUT, she
uses a DSL connection to get to her Citrix session, and therefore all
software and network connections are preferably running in the main
office.



Thanks in advance, C