I have been trying to resolve this but with no success and dont know where to look.

I'm trying to send a logfile with mutt, like this
mutt -s "Backuplog" -a /tmp/filescopied.log.gz my@mail.net < /var/log/zimbrabackup.log
It works to an internal adress on the zimbra server, but not to a external account, ex my gmail account

cannot figure out why.

running zimbra 6 ocn debian 5. Sending mail is working from zimbra to external accounts, i am using a smart host relay for this if it matters

I've no other MTAs running

I've made a symbolic link from zimbras post fix to /usr/sbin/postfix

someone hwo have any clues?