GitLab

* doc/misc/smtpmail.texi (Queued delivery): Document it (bug#49709).

* lisp/gnus/message.el (message-multi-smtp-send-mail): Store
variables.

* lisp/mail/smtpmail.el (smtpmail-queue-mail): Mention it.
(smtpmail-store-queue-variables): New variable.
(smtpmail-send-it): Store SMTP variables if requested.
(smtpmail-send-queued-mail): Restore variables.