We have a very strange problem where email messages sent from Outlook launched from Citrix are not being sent and are getting stuck in the outbox on the local client version of outlook. This doesn't happen all of the time but we have been able to reproduce the problem in the following way
Outlook is closed in Citrix session and on the local pc (confirmed by checking task manager and citrix director) open document with say word or Excel using the citrix version of the application, select File "save and send" enter recipients of the email and click send, email disappears and looks to have been sent, Outlook is still closed in Citrix and on the local PC.
Recipient doesn't receive the message, the message is not visible in Message trace on Office 365, the message cannot be found by E-discover on Office 365, I give myself permission to the users mailbox, the message is not visible in any folder when viewing the mailbox in outlook web app or local or citrix outlook.
If the affected user opens the local copy of outlook the message is immediately sent and can be viewed in message trace, e-discovery and arrives with the recipient. If outlook on citrix is opened the message is not available and is not received, the recipient can be a shared mailbox or user mailbox. I have confirmed he message is stuck in the local Outlook outbox by having the user reproduce the issue and disconnecting the PC from the network before opening the local copy of outlook and checking the outbox.
outlook version is 2010 on citrix and pc using Office 365, in Citrix online mode is used, local PC client has outlook cached mode enabled, both are set to send immediately when connected, outlook is not set to work offline and shows as connected at all times.
The issue has been going on for some time, Initially we thought thata local copy of Word or Excel was being launched and sending the messages to the local cached copy of outlook then sitting in the outbox due to outlook being closed, this is not the caase. It has been suggested that users should leave the locally installed outlook open at all times however this is confusing for many users as they have been told to use citrix for all applications
I have worked with Office 365 support and have confirmed there is no delay on the Office 365 side as the first time Office 365 message trace 'sees' the stuck message is when the user launches the local copy of outlook and the message is delivered to the recipient, we have confirmed that the message is in the local outlook Outbox.
If you have got this far thanks for sticking with me, any help or advice is much appreciated.