Why does swiftmailer send emails from the old address even though it has already been changed?

Question

Drupal

After transferring to hosting, swiftmailer stopped sending emails.
I configured it for mail from the hosting, but in errors it persistently sends from the old test address that I used earlier before setting up the hosting. Outputting an error like this:

Error sending mail (from <OLD>@gmail.com to <TEST>@gmail.com with no response for to).

Answer 1

How do you send mail? If you use some module with queues, for example https://www.drupal.org/project/queue_mail, in this case, letters with the old email could remain in the queue, which now cannot be sent. Then you just need to clear the queue.