I am seeing a similiar issue now on my personal laptop when software delivers a message to the locally running exim via SMTP. The software never returns until it times out, redelivering the message to the local exim on the next try. Exim has the message on its queue as well, but the process handling is is stuck:
2020-06-30 14:21:38 1jqFGc-009l6x-8M <= mh+usenetspam1...@zugschl.us H=localhost [127.0.0.1] P=smtp S=2649 2020-06-30 14:45:27 Start queue run: pid=2326372 2020-06-30 14:45:27 1jqFGc-009l6x-8M Spool file for 1jqFGc-009l6x-8M is locked (another process is handling this message) 2020-06-30 14:45:27 End queue run: pid=2326372 2020-06-30 15:15:27 Start queue run: pid=2326592 2020-06-30 15:15:27 1jqFGc-009l6x-8M Spool file for 1jqFGc-009l6x-8M is locked (another process is handling this message) 2020-06-30 15:15:27 End queue run: pid=2326592 2020-06-30 15:45:27 Start queue run: pid=2326833 2020-06-30 15:45:27 1jqFGc-009l6x-8M Spool file for 1jqFGc-009l6x-8M is locked (another process is handling this message) 2020-06-30 15:45:27 End queue run: pid=2326833 2020-06-30 16:15:27 Start queue run: pid=2327080 2020-06-30 16:15:27 1jqFGc-009l6x-8M Spool file for 1jqFGc-009l6x-8M is locked (another process is handling this message) 2020-06-30 16:15:27 End queue run: pid=2327080 a kill -9 on the stuck process is needed so that the next queue runner picks the message up and eventually delivers it. The messages injected again by the originating software causes repeat messages. I cannot confirm yet that this is related to sleeping, but I can confirm that messages delivered via /usr/lib/sendmail go out fine without delay, so this is probably related to the SMTP receiver. After pkill -9 exim and restarting the exim daemon things are fine again, a reboot is not needed. Greetings Marc -- ----------------------------------------------------------------------------- Marc Haber | "I don't trust Computers. They | Mailadresse im Header Leimen, Germany | lose things." Winona Ryder | Fon: *49 6224 1600402 Nordisch by Nature | How to make an American Quilt | Fax: *49 6224 1600421