Saturday, June 29, 2024

Yesterday I sent a next newsletter to my friends. I manage the recipient list in Thunderbird and set it as the bcc field (because we don’t want everybody to see the other recipients).

My list holds 375 addresses, 43 of which are at skynet.be. And Skynet (which is now a part of Proximus) accepts a maximum number recipients per connection. After the 5th recipient it says “Too many recipients”. But the Postfix on our mail server doesn’t give up. It tries again after 5 minutes, then after ten minutes, after 20 minutes… Here is how that looks in the mail.log file:

$ sudo grep joe.doe /var/log/mail.log
Jun 28 21:57:35 saffre-rumma postfix/smtp[2252573]: 3B984211FB: to=<joe.doe@skynet.be>, relay=mx.glb.proximus.be[195.238.22.25]:25, delay=22, delays=20/0.97/0.14/0.24, dsn=4.0.0, status=deferred (host mx.glb.proximus.be[195.238.22.25] said: 459 Too many recipients (RL) (in reply to RCPT TO command))
Jun 28 22:03:21 saffre-rumma postfix/smtp[2252792]: 3B984211FB: to=<joe.doe@skynet.be>, relay=mx.glb.proximus.be[195.238.20.25]:25, delay=367, delays=367/0.08/0.24/0.19, dsn=4.0.0, status=deferred (host mx.glb.proximus.be[195.238.20.25] said: 459 Too many recipients (RL) (in reply to RCPT TO command))
Jun 28 22:13:21 saffre-rumma postfix/smtp[2253003]: 3B984211FB: to=<joe.doe@skynet.be>, relay=mx.glb.proximus.be[195.238.20.25]:25, delay=967, delays=966/0.04/0.82/0.16, dsn=4.0.0, status=deferred (host mx.glb.proximus.be[195.238.20.25] said: 459 Too many recipients (RL) (in reply to RCPT TO command))
Jun 28 22:33:20 saffre-rumma postfix/smtp[2253231]: 3B984211FB: to=<joe.doe@skynet.be>, relay=mx.glb.proximus.be[195.238.20.25]:25, delay=2166, delays=2166/0.03/0.11/0.13, dsn=4.0.0, status=deferred (host mx.glb.proximus.be[195.238.20.25] said: 459 Too many recipients (RL) (in reply to RCPT TO command))
Jun 28 23:13:21 saffre-rumma postfix/smtp[2253484]: 3B984211FB: to=<joe.doe@skynet.be>, relay=mx.glb.proximus.be[195.238.22.25]:25, delay=4568, delays=4567/0.04/0.44/0.66, dsn=4.0.0, status=deferred (host mx.glb.proximus.be[195.238.22.25] said: 452 #4.5.3 Too many recipients. (in reply to RCPT TO command))
Jun 29 00:23:22 saffre-rumma postfix/smtp[2254227]: 3B984211FB: to=<joe.doe@skynet.be>, relay=mx.glb.proximus.be[195.238.20.25]:25, delay=8768, delays=8767/0.03/0.19/0.47, dsn=2.0.0, status=sent (250 ok:  Message 3727612 accepted)