Hello,
replying to myself, this problem is indeed related to GnuTLS in the Debian strech compile of Exim4. Once I did this: sudo apt-get update sudo apt-get upgrade sudo apt-get build-dep exim4 sudo apt-get install --no-install-recommends devscripts fakeroot apt-get source exim4 perl -i -pe 's/^\s*#\s*OPENSSL\s*:=\s*1/OPENSSL:=1/' exim4-*/debian/rules cd exim4-* dch -l +openssl 'rebuild with openssl' debian/rules binary The problem is solved. Sorry I have no time to debug the GnuTLS issue further. sincerely, Andreas we have a well configured mail server with exi 4.89 on Debian 9, and use a LetsEncrypt certificate for SMTP with STARTTLS on port 25 as well as SMTPS on port 465. Everything works well, except: 2017-11-27 13:22:55 TLS error on connection from mail-oln040092070016.outbound.protection.outlook.com (EUR03-AM5-obe.outbound.protection.outlook.com) [40.92.70.16] (send): The specified session has been invalidated for some reason. 2017-11-27 13:23:46 1eJILV-0001Gg-K3 TLS error on connection from mail-oln040092071027.outbound.protection.outlook.com (EUR03-DB5-obe.outbound.protection.outlook.com) [40.92.71.27] (recv): Error in the pull function. It seems only this specific server will fail to connect with TLS with "Error in the pull function". This is the only occasion where we see this message, everything else works fine. -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
