Sent messages are currently directed to the Sent Messages folder not Sent Mail folder.
Why are there two folders listed?
I amended /etc/dovecot/conf.d/15-mailboxes.conf and commented out Sent Messages, moved existing messages from that folder to Sent Mail, applied configuration. Then stopped and restarted Dovecot. Finally, I rebooted the server to apply the new configuration. None of these worked and the two folders still show and messages still go to the Sent Messages folder.
I do not mind which is shown but how do I set it so only one shows and all the sent mail goes to it?
Folders are historically handled by the mail client(s), and have different conventions that vary quite a bit.
The “Sent mail” folder might be generated by Usermin (I don’t recall, but whatever we called it was based on what some other mail clients were using at the time). You can configure it in Webmin->Webmin->Usermin Configuration->Usermin Module Configuration->Read Mail->Default User Preferences->Sent mail folder name
I’m not sure changing this will apply to existing users, as I suspect it copies in the default config on first user visit to the Read Mail module. But, it’s also user configurable in Mail Preferences from within Usermin.
Weird. Sometimes it goes to sent mail and other times it goes to sent messages. Sent messages is syncing with my mail client so I will leave it with that.