Smtp_should_reject 400 bad request em nounces

Bug
1

Hi!

I am basically having the exact same issue described here: Configure direct-delivery incoming email for self-hosted sites with Mail-Receiver - #482 by Carleas

The problem seems to be that the bounces I am receiving don’t come with a from so when the API call is made like https://forum.example.com/admin/email/smtp_should_reject.json?from=&to=replies+verp-326f6e22828d2543ba65497a47608f13@mail.forum.example.com it returns a 400 with:

{"errors":["param is missing or the value is empty or invalid: from"]}

here’s a bit more of the mail-receiver logs

Nov 03 07:34:53 mail postfix/smtpd[1044]: connect from v-108-120-yyy-74-srvr1.xxx.com[74.91.xxx.108]
<19>Nov  3 07:34:53 discourse-smtp-fast-rejection[1048]: Failed to GET smtp_should_reject answer from https://forum.example.com/admin/email/smtp_should_reject.json: 400<22>Nov  3 07:34:53 policyd-spf[1049]: : prepend Received-SPF: None (no SPF record) identity=helo; client-ip=74.91.xxx.108; helo=v-148-29-xxx-192-srvr1.xxx.com; envelope-from=<>; receiver=mail.forum.example.com Nov 03 07:34:53 mail postfix/smtpd[1044]: NOQUEUE: reject: RCPT from v-108-120-yyy-74-srvr1.xxx.com[74.91.xxx.108]: 450 4.7.1 <replies+verp-326f6e22828d2543ba65497a47608f13@mail.forum.example.com>: Recipient address rejected: Internal error, API request failed; from=<> to=<replies+verp-326f6e22828d2543ba65497a47608f13@mail.forum.example.com> proto=ESMTP helo=<v-148-29-xxx-192-srvr1.xxx.com>

However, even if it came with a right from (putting my email there) it comes back with

{"reject":true,"reason":"Mail to this address is not accepted. Check the address and try to send again?"}

So it would’ve rejected that as well…

Am I missing something on the config? I can’t figure it out

1 curtida
2

Hello! Sorry but it appears your topic found no takers. Were you able to resolve your problem on your own?

What mail provider are you using?

3

No, unfortunately, I am not receiving the bounces…

I am using an SMTP server from a CPanel though

4

What about your outbound email provider? Are you using mailgun or some other transactional email provider?

5

Nope. The same SMTP, outgoing is working perfectly, and incoming for topics it’s also arriving perfectly, the problem is bounces are not visible to the forum so it keeps trying and I get scolded by my hosting provider

6

I’m slipping this across to #hosting.

The typical official answer for this sort of thing unfortunately is to say “email is hard”. You will get much better results if you use a transactional email provider.

If you have a budget, you can post in Marketplace or I can move this topic there for you.

7

Thanks for at least taking the time to look into this with me !!

1 curtida
14

Hi DevTeVe,

I’ve reviewed the code in question and I believe you are right - I think the smtp_should_reject code may be incorrectly rejecting bounce messages and replies.

I’m escalating this internally.

In the meanwhile, if you disable the discourse-smtp-fast-rejection policy filter does it allow mail to flow?

2 curtidas
15

Wow! Thank you for escalating it! I was a little bit hopeless hahaha! I will try disabling discourse-smtp-fast-rejection (although I am not sure how to do that, but I will search and report back)

1 curtida
17

If you can remove this line from the mail-receiver postfix config file:

smtpd_recipient_restrictions = check_policy_service unix:private/policy

This should do the trick - I haven’t tested this but I think it’ll work:

postconf -e "smtpd_recipient_restrictions ="
1 curtida
18

Success!

image
image2900×698 112 KB

I am making my mail-receiver.yaml like this (in the meantime or forever? @supermathie)

# this is the incoming mail receiver container template
##
## After making changes to this file, you MUST rebuild
## /var/discourse/launcher rebuild mail-receiver
##
## BE *VERY* CAREFUL WHEN EDITING!
## YAML FILES ARE SUPER SUPER SENSITIVE TO MISTAKES IN WHITESPACE OR ALIGNMENT!
## visit http://www.yamllint.com/ to validate this file as needed

base_image: discourse/mail-receiver:release
update_pups: false

expose:
  - "25:25"   # SMTP

env:
  LC_ALL: en_US.UTF-8
  LANG: en_US.UTF-8
  LANGUAGE: en_US.UTF-8

  ## Where e-mail to your forum should be sent.  In general, it's perfectly fine
  ## to use the same domain as the forum itself here.
  MAIL_DOMAIN: community.example.com
# uncomment these (and the volume below!) to support TLS 
  POSTCONF_smtpd_tls_key_file:  /letsencrypt/community.example.com/community.example.com.key
  POSTCONF_smtpd_tls_cert_file:  /letsencrypt/community.example.com/community.example.com.crt
  POSTCONF_smtpd_tls_security_level: may
  POSTCONF_myhostname: community.example.com
  POSTCONF_mynetworks: "127.0.0.0/8 [::1]/128 [fe80::]/64 172.17.0.0/16"
  POSTCONF_smtpd_recipient_restrictions: ""
  ## The base URL for this Discourse instance.
  ## This will be whatever your Discourse site URL is. For example,
  ## https://discourse.example.com. If you're running a subfolder setup,
  ## be sure to account for that (ie https://example.com/forum).
  DISCOURSE_BASE_URL: 'https://community.example.com'

  ## The master API key of your Discourse forum.  You can get this from
  ## the "API" tab of your admin panel.
  DISCOURSE_API_KEY: <YOURKEY>

  ## The username to use for processing incoming e-mail.  Unless you have
  ## renamed the `system` user, you should leave this as-is.
  DISCOURSE_API_USERNAME: system

volumes:
  - volume:
      host: /var/discourse/shared/mail-receiver/postfix-spool
      guest: /var/spool/postfix
# uncomment to support TLS
  - volume:
      host: /var/lib/caddy/.local/share/caddy/certificates/acme-v02.api.letsencrypt.org-directory/
      guest: /letsencrypt
1 curtida
19

Let’s go with “for now” and we’ll update this topic when we have more news.

3 curtidas
20

Thank you very much! I really didn’t expect this to move any further but now it’s perfect and im receiving all the other bounces!

3 curtidas