undeliverable notice

undeliverable notice

I have 2 users who use outlook at my organization.  Sometimes when they send an email it goes into the retry mail queue and just keeps a continuous loop of trying to resend the emails and they never get an undeliverable.  Is there a way to have the emails not go into that retry queue and if they fail to send an undeliverable.

It only happens with outlook on the computer as I use Apple Mail and it comes back right away.

Thanks,

Ted