I noticed that nullmailer had problems sending emails from 3 different gentoo systems of mine. In most cases, I found the following error in nullmailer's log: Starting delivery: host: smtp.gmail.com protocol: smtp file: 1553319967.12736 From: <REDACTED> to: <REDACTED> Message-Id: <1553319967.532067.12735.nullmailer@REDACTED> smtp: Failed: Sending failed: Protocol error In some very few cases, nullmailer was able to send the email after many attempts. After some investigation and experimentation, it appears that these problems are due to an incompatibility issue between all versions of nullmailer earlier than 2.2 and version 3.6 and newer of gnutls. This is supported by the following item in nullmailer's changelog for 2.2: - Fixed compatibility issue with gnutls 3.6 (and possibly others). which corresponds to this upstream commit [1]. Therefore, I propose that all ebuilds for <mail-mta/nullmailer-2.2 are updated so that they depend on <net-libs/gnutls-3.6. Note that this also means that mail-mta/nullmailer-2.2 has to be stabilized, since gnutls 3.6 is already stable. [1] https://github.com/bruceg/nullmailer/commit/a51499eb296f437712ff72d7425953559274890d
This might be related to #651238.
Had this issue today as well. Updating to mail-mta/nullmailer-2.2 fixed it