There is a Mail Universal Security group for all Users in a company, so the e-mail should arrive to everyone, but couple of users dont receive the e-mail. The sender is not getting any undelivered error messages. There is no quota set up for mailboxes. Sending an e-mail directly to the user; works fine. Those users are the part of the group and its show in outlook as well when you send an e-mail. Does anyone have any idea what can cause such a glitch?

have you tried tracking the message or use the mailflow troubleshooter in the EMC toolbox?

I've run the tests you suggested and no error messages were reported. My thoughts are that it could be some outlook settings, but I really doubght about it.Any other suggestions?

Sure, does the message show up in OWA? that would eliminate outlook as the culprit.

Nah it does not For time being I just created the redirection rule from my mail box.