On 3G and outgoing mail not sending? Chances are, you need to set the SMTP server specific to your network. Here’s the list that may grow over time: ...
If you’re getting the "5.3.4 Messag exceeds fixed limit” error, check on the default vs set values in your /etc/postfix/main.cf using postconf -d (for the default) and postconf -n (for the ...