Some notification mails as marked as SPAM because of URI_COUNT_ODD and MISSING_TO rules (rspamd)

Added by R Pommier 3 months ago

Hi,

Some of the notification mails fall in SPAM folders because of some checks of rspamd:

URI_COUNT_ODD

A rule of rspamd [URI_COUNT_ODD, increase bad-score of 1 point] check if there is the same number of URI in the part text/plain than the part text/html (https://github.com/rspamd/rspamd/discussions/3831 for explanations).

In the text/plain, one of the first lines is:

Issue #xxxx has been updated by Firstname Lastname.

In the text/html, the same line is:

Issue <a href=3D"https://.myredmine.com/issues/xxxx#change-48909" style=3D"color:#169">#xxxx</a> has been updated by Firstname Lastname.

For this, I understand we could not add URI each time we write issue number, but how to do to avoid this flag?

Idem, in "Files" listing, there is a link in the HTML part but not in text/plain part.

So, if there is a file, the URI count is odd (because in text/plain, 1 missing for the first line + 1 missing for the "file" line, -> 2 missing URI's -> odd)

MISSING_TO

Another rule [MISSING_TO, increase bad-score of 2 points] check if there is a header "To: ".

I don't know why there is not header "To: ". it's a specific setup (a setting or plugin), or global in Redmine?


Thanks for your suggestions!

Replies (3)

RE: Some notification mails as marked as SPAM because of URI_COUNT_ODD and MISSING_TO rules (rspamd) - Added by Holger Just 3 months ago

I would consider the URI_COUNT_ODD to be, well, odd :) Trying to fulfill this rule would mean that we add any convenience link we add in HTML mails also to the text part, even if it only marginally helps. I don't believe that this would add a lot of benefit to Redmine. I'd thus rather follow the viewpoint of fa11enangel in the issue you linked to.

As for the missing To header, previous Redmine versions had a Setting where notification mails would not include the list of recipients in the To header but would instead set them in a BCC header. With this enabled, you could avoid leaking the email addresses of other users who received the notifications (as older Redmine versions have sent single notifications mails to many users). Since Redmine 4.0, we are sending each users their own notification mail. The previously relevant setting however was only finally dropped in Redmine 5.0.

Thus, you could either upgrade your Redmine or if you have to keep the old version (>= 4.0), you could also disable the BCC setting in Administration -> Settings -> Notifications

RE: Some notification mails as marked as SPAM because of URI_COUNT_ODD and MISSING_TO rules (rspamd) - Added by R Pommier 3 months ago

Hi,

Thanks for your reply!

I didn't see the bcc settings in admin. I just checked off, and will see the result.

Indeed, the rule URI_COUNT_ODD is strange and not applicable in many cases.
I will see if the bcc settings will be enough to "unspam" my emails. If not, I will check to disable, mailserver side, the rule URI_COUNT_ODD.

I let you know in the next days/weeks.

RE: Some notification mails as marked as SPAM because of URI_COUNT_ODD and MISSING_TO rules (rspamd) - Added by R Pommier 3 months ago

Hi,

Indeed, check this option is enough to don't mark notification mails as spam.

Thank you!

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