On Thu, 18 Jun 2020 at 15:03, Wietse Venema <wie...@porcupine.org> wrote: > > Dominic Raferd: > > I understand the reason for smtp_line_length_limit and for its default > > value of 998, which is of course good. > > It breaks DKIM signatures, it is needed only for mail that is sent > via SMTP, and worse, it breaks lines in the middle of a multibyte > character (and of course in the middle of a word, in the middle of > an HTML tag, and so on). So it really shuod not be considered a > reliable solution. > > The main reason smtp_line_length_limit exists is to prevent other > MTAs from breaking MIME-formatted mail, where one huge message > header could cause all message content to become exposed in the > underlying encoding (base64 or quoted-printable). > > If your problem is with cron job outputs that aren't sent across > the Internet, you could just disable this behavior by setting the > limit to zero, and by configuring other MTAs similarly. > > Alternatively, as these cron jobs are under local control, you could > massage their output through a program that fixes long lines. >
Thanks for your answer and explanation. Your second suggestion is what I do, but it is difficult to catch all instances. I have now followed your first and set the limit to zero (which I believe is undocumented as a way to turn off automatic line-breaking). Actually I am relaying into Gmail so it will be interesting to see if it copes with overlong lines. > The sendmail command is a bad place for doing this, why not the > cleanup daemon? Answering that question is way above my pay grade.
