I'm kinda confused on exactly what stop emails from forwarding from one of our users. All she did was change her greeting and she stop receiving voicemails. I check her message actions and for voicemails settings are Accept and Relayed to her SMTP email address which is correct.
Are you sure she's actually getting voicemails recorded since? I ask because it's possible to turn off the announcement to leave a message after the beep. If that's off, the caller might not realize to leave a message after her new greeting.
Assuming other users are getting their voicemails relayed to email, I suggest looking at the SMTP smarthost logs. Does it receive the email? Is it, or some other element of the email infrastructure, quarantining it?