I have an issue with my Zimbra server. It has 205 emails stuck in deferred queue. Internally it works fine, receives and delivers messages normally. If I sent an email from an external account (outlook, gmail, etc.) I receive it, but when I answer that email it does not deliver it.
I'm using ZCS 7.1.0_GA_3140/Ubuntu 8.04 LTS.
If you need any additional information, please let me know.
Updating: Since yesterday I reviewed this information and tested those "solutions", but didn't work for me: