SMTP Simple mail transfer protocol
SMTP / Email spoof tests
Debug smtp sasl starttls authentication
Connect and move to tls protected channel
$ openssl s_client -starttls smtp -crlf -connect vigor.nz:25 ehlo testconnection auth plain (base64encodedstring)
test sasl (/etc/sasldb2 )with
# sasldblistusers2 # testsaslauthd -u user -p password -f /var/spool/postfix/var/run/saslauthd/mux
add user to sasl
saslpasswd -c -u mail.example.com -a smtpauth test
view postfix smtp logs using journalctl
journalctl -u postfix@-.service -f
Check tls certificate on smtp server
# echo "quit" | openssl s_client -starttls smtp -crlf -connect <smtp.host>:25 | openssl x509 -noout -text | grep DNS:
...