Description of problem: sendmail 8.15.2-16.fc26 is quietly changing milter-greylist's transient 451 return codes into hard-fail 550 return codes which it then gives to the remote MTA. This causes a hard bounce and the email will never be retried, completely breaking greylisting/email. It's really insidious because email doesn't just stop: there are still 2 cases where emails get through: the tuple is in gm's hard or auto-whitelist, or the end user resends the email after the gm timeout period. So many emails will get through and mail admins may not know there is a problem until they start getting some phone calls about missing emails... dnf downgrade sendmail to 8.15.2-14.fc26 solves this bug as a workaround until a new rpm is released. Version-Release number of selected component (if applicable): sendmail 8.15.2-16.fc26 milter-greylist-4.6.2-3.fc26.x86_64 How reproducible: always Steps to Reproduce: 1. setup sendmail with milter-greylist 2. test it remotely (some host NOT whitelisted, so localhost is usually out): 3. telnet problemsendmailhost.com 25 HELO problemsendmailhost.com MAIL FROM:yourname RCPT TO: <validuser> Actual results: 550 <validuser>... 451 4.7.1 Greylisting in action, please come back later Expected results: 451 4.7.1 Greylisting in action, please come back later (which is what 8.15.2-14.fc26 gives) Additional info: This sounds exactly like the bug mentioned here in 2015 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=807258 which it says was fixed upstream, but in 8.16? Seems like someone maintaining 8.15 hosed this patch.
Thanks for info. We had older version of this patch in Fedora which introduced this problem
sendmail-8.15.2-19.fc26 has been submitted as an update to Fedora 26. https://bodhi.fedoraproject.org/updates/FEDORA-2017-b2b8e47545
sendmail-8.15.2-19.fc26 has been pushed to the Fedora 26 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2017-b2b8e47545
sendmail-8.15.2-19.fc26 has been pushed to the Fedora 26 stable repository. If problems still persist, please make note of it in this bug report.