[pmg-devel] [PATCH pmg-api 0/2] fix smtputf8 handling if disabled in postfix

Stoiko Ivanov s.ivanov at proxmox.com
Mon Jan 23 16:55:19 CET 2023

This series addresses an issue some of our users reported in our
community forum with pmg-api_7.2-3:
* the decision if smtputf8 is needed is based on the envelope-addresses
  and the headers (if they contain non-ascii characters we use SMTPUTF8
* this breaks environments where SMTPUTF8 is disabled (mostly because
  some downstream servers do not support this), but mails still contain
  non-ascii data (while this is against the relevant rfc, which say that
  header-data must contain only ascii characters (and should be encoded
  with MIME-words otherwise), it is seemingly quite common in the wild)

one testmail I got from a user from the forum had the From header
correctly encoded, but added an X-DFrom header with the unencoded from.

The first patch simply drops the header-inspection and should enable
most of the reporters to receive mail again.

The second patch tries to address the smtputf8 issue a bit differently
than what we currently do
- For mails received via SMTP it simply sets SMTPUTF8 if the original
  postfix processes sent pmg-smtp-filter the mail with the flag, and
  does not set it otherwise
- For locally generated mail it detects if its needed by checking the
  envelope-addresses and the headers for non-ascii characters.

This should follow postfix own functioning quite closely:

processing by pmg-smtp-filter should not change the need for the flag,
since we don't rewrite envelope-addresses, and modify filed does
mime-encode the resulting header.

Sending as two patches, since the first one would be good to get out
soon (as it's affecting a few setups), while the second one might
benefit from a bit more testing (I did some tests, which all looked
good, but might have overlooked some cases)

Stoiko Ivanov (2):
  utils: skip checking headers for non-ascii characters
  smtputf8: keep smtputf8 from incoming postfix, detect for local mail

 src/PMG/API2/Quarantine.pm |  7 ++++++-
 src/PMG/RuleDB/Notify.pm   |  6 +++++-
 src/PMG/SMTP.pm            |  7 ++++++-
 src/PMG/Utils.pm           | 12 +++++++++---
 4 files changed, 26 insertions(+), 6 deletions(-)


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