You can remove Postfix and use SSMTP as it has easier configuration.
yum install ssmtp ca-certificates mutt
Follow instructions at https://golb.hplar.ch/2018/06/send-only-email.html
To get desired sender (username@hostname) when using mutt to send, add this line to /etc/ssmtp/ssmtp.conf:
FromLineOverride=YES
Add these lines to the global /etc/Muttrc.local (easier than adding it to each user's $HOME/.muttrc):
set from = "`whoami`@`hostname`" set realname = "`whoami`@`hostname`"
Successful test via manual send:
mutt -s "Test4" [email protected] </dev/null
Successful test via crontab:
\* * * * * /path/to/bin/mutt_test.bash > /path/to/logs/mutt_test.log
The mutt_test.bash test script has this for content:
#!/bin/bash date=`date` mutt -s "$date bash mutt test" [email protected] </dev/null