I understand the reason for smtp_line_length_limit and for its default value of 998, which is of course good.
But it is an occasional problem for me that this wrapping action is only applied at smtp stage and not earlier; in particular it is after any (open)dkim milter adds its key, because smtp's wrapping means that the key then becomes invalid. The standard answer would be that it is the responsibility of an MUA to ensure that emails do not break the RFC, so then smtp would not have to fix a problem that is not of its own making. But postfix's sendmail does not honour the RFC or the smtp_line_length_limit value and happily submits emails with overlong lines, and this is where my problem occasionally arises, say when emailing output from a cron job. I have various workarounds, and can imagine more. But the elegant solution would be to make postfix's sendmail program honour and enforce the smtp_line_length_limit parameter, or (better, and backwards-compatible) to create another parameter dictating whether sendmail would do this (e.g. sendmail_fix_line_length as yes/no[default]). Obviously the limit should be applied after any sendmail_fix_line_endings setting has been processed. Or an entirely independent sendmail_line_length_limit parameter could be created (if it is awkward to have sendmail honouring an smtp_ parameter). Is that possible or is it a bad idea?
