Claws Mail frequently saves a draft of a new mail in the IMAP drafts folder while it is being created. Once the mail has been sent, the draft remains in the draft folder and appears as unfinished in other clients although it can be considered finished when sent. Claws Mail should delete a draft when the corresponding mail is sent.
They are. Unless you use gmail and its 'irregular' version of imap.
It's not gmail.
You need to provide more information, because this WORKSFORME
What do you need? I have 3 accounts configured. It happens regularly with one of them -- which is not Gmail. When sending mail through Gmail, I have never experienced that bug so far. I rarely use the third one for sending, so I don't know if it would happen there too.
The network log or --debug output is a good starting place.
FWIW, I see this too, have for some time. I've never had a chance to try to figure out what circumstances cause a draft to stay around. Not gmail here either; it's a dovecot IMAP server.
Created attachment 1711 [details] log
It just happened to happen again, so I could cut out the relevant parts from the log. From line 405 to 441 the mail is being sent. In line 899 you can see that there is a mail in the drafts folder - the one I just sent.
I've seen this behavior with dovecot mail server with pretty much default config. In my case during email composing several drafts showed in drafts folder and after send they remained there for minutes or hours before their deletion. Client was always TB. But I did not considered it to be too big issue to report it.
I left one draft of a mail that I sent yesterday in the draft folder, but it didn't get deleted automatically as daniel said.