We have noticed the following problem: Sometimes e-mails about forum activity are sent twice. They have the same Message-ID, but are delivered via SMTP as two separate e-mails. This is a bit annoying for users, is this a known bug?
We run cron every minute, we have a few scheduled tasks that take some minutes to run, is it possible that the e-mail-sending task is executed twice in two active cron runs? As I understand the source code, there's a lock that should prevent this.