Why is sendmail only logging internal messages to /var/log/mail?

Question

I'm pretty sure that in the past my sendmail (triggered from PHP) was logging messages sent from PHP to the MTA and also MTA to the recipient. Although emails are received by the recipient and I can see the logs with journalctl -u sendmail I'm not seeing the external communication in /var/log/mail.log (I am seeing the internal). What setting to I need to enable?

I am using rsyslog which I haven't changed and checked permissions (as per https://www.claudiokuenzler.com/blog/657/rsyslog-ubuntu-xenial-no-logging-var-log-mail.log-permissions) on the log folder (0775) and permissions on the mail.log are 0777 and syslog:adm.

This is a Ubuntu 16 box.

Answer 1

It turns out all I needed to do was restart rsyslog as per https://unix.stackexchange.com/questions/165201/postfix-no-longer-logs-to-var-log-mail-after-it-has-been-deleted-and-re-created (although this relates to Postfix which is not my query)