Continuing the discussion from Email receive issue: I implemented valid_recipients filtering via postfix/valid_recipients and populated /etc/postfix/valid_recipients. Since then, I’m seeing repeated warnings and inbound connection attempts every ~6 minutes. Here’s a sanitized segment of my log. :warning: Exact log output Jul 23 05:13:40 ubuntu-mail-receiver postfix/smtpd[2265]: warning: /etc/postfix/valid_recipients, line 1: expected format: key whitespace value -- ignoring this line Jul 23 05:13:40 ubuntu-mail-receiver postfix/smtpd[2265]: warning: /etc/postfix/valid_recipients, line 2: expected format: key whitespace value -- ignoring this line ... Jul 23 05:13:40 ubuntu-mail-receiver postfix/smtpd[2265]: warning: /etc/postfix/valid_recipients, line 16: expected format: key whitespace value -- ignoring this line These warnings appear every few minutes, aligned with repeated unauthenticated connection attempts like: Jul 23 05:13:40 ubuntu-mail-receiver postfix/smtpd[2265]: warning: hostname unassigned.quadranet.com does not resolve to address 198.55.98.3 Jul 23 05:13:40 ubuntu-mail-receiver postfix/smtpd[2265]: connect from unknown[198.55.98.3] Jul 23 05:13:40 ubuntu-mail-receiver postfix/smtpd[2265]: disconnect from unknown[198.55.98.3] ehlo=1 auth=0/1 quit=1 commands=2/3 This same pattern repeats from 198.55.98.3 over dozens of cycles throughout the hour. :white_check_mark: Legitimate mail passes through Just to confirm, legitimate deliveries (e.g. from Microsoft 365) are working: Jul 23 05:46:53 ubuntu-mail-receiver postfix/smtpd[2290]: connect from mail-uksouthazon11020141.outbound.protection.outlook.com[52.101.196.141] Jul 23 05:46:54 opendkim[25]: D3D4A1BF983: DKIM verification successful Jul 23 05:46:54 opendmarc[40]: D3D4A1BF983: MYDOMAINNAME.com pass Jul 23 05:46:54 ubuntu-mail-receiver postfix/pipe[2296]: to= , relay=discourse, status=sent (delivered via discourse service) :red_question_mark:Questions Are the /etc/postfix/valid_recipients warnings responsible for triggering the repeated connections? Should I expect Postfix to loop on these entries if the file is misformatted? Would you recommend temporarily disabling check_recipient_access to test stability? Is there a preferred example of a valid_recipients file used with the mail-receiver container for Discourse? :puzzle_piece: My main.cf line (for reference) smtpd_recipient_restrictions = check_recipient_access hash:/etc/postfix/valid_recipients, reject Would really appreciate some guidance here — thanks in advance!

How to Reload Postfix with Discourse AI Ethsim2: [image] open_mailbox_with_raised_flag Repeated Postfix warnings and connections after valid_recipients implementation Support Continuing the discussion from Email receive issue: I implemented valid_recipients filtering via postfix/valid_recipients and populated /etc/postfix/valid_recipients. Since then, I’m seeing repeated warnings and inbound connection attempts every ~6 minutes. Here’s a sanitized segment of my log. warning Exact log output Jul 23 05:13:40 ubuntu-mail-receiver postfix/smtpd[2265]: warning: /etc/postfix/valid_recipients, line 1: expected format: key whitespace value -- ignoring this line Jul 23 0… is it correct that i did modify main.cf DiscourseHelper: Searching Searching for: Is it necessary or recommended to manually modify postfix main.cf when implementing a valid_recipients file for recipient restrictions in a Discourse mail-receiver container? Should main.cf be edited directly, or are all recommended changes handled by docker environment variables or launcher yml settings for Discourse mail-receiver setups? Reading Read: 📬 Repeated Postfix warnings and connections after valid_recipients implementation No, it is not necessary or recommended to manually modify main.cf in the mail-receiver container for valid recipient filtering when following Discourse’s standard setup. Correct Approach: Discourse’s official mail-receiver guide and container setup is designed so you do not edit main.cf by hand. Instead: You should use the mail-receiver.yml’s env section to set Postfix parameters—specifically, using an environment variable like: POSTCONF_smtpd_recipient_restrictions: texthash:/etc/postfix/valid_recipients or, if you use the older config style: POSTCONF_smtpd_recipient_restrictions: check_recipient_access hash:/etc/postfix/valid_recipients, reject Docker/launcher correctly applies these settings on container startup, injecting them into Postfix without needing to directly edit files. Editing main.cf directly can cause conflicts or be overwritten on container rebuilds. It’s also easy to break things (such as file format or recipient mapping) this way. About Your Error: The warnings you see: warning: /etc/postfix/valid_recipients, line 1: expected format: key whitespace value -- ignoring this line are caused by a misformatted valid_recipients file—not by how the config is set (env vs main.cf). Make sure your entries are like: alloweduser@yourdomain.com OK another@yourdomain.com OK default REJECT No colons, equals, or commas—just the address, whitespace, and OK (or REJECT). Do not edit main.cf unless you have a highly advanced, fully custom configuration and understand exactly what you are doing. All normal instructions (including valid recipient and sender filtering) are performed by setting environment variables in mail-receiver.yml. References: Configure direct-delivery incoming email for self-hosted sites with Mail-Receiver Customize direct-delivery Postfix configuration Your referenced topic: Repeated Postfix warnings and connections after valid_recipients implementation Summary: You should not need to touch main.cf for standard Discourse mail-receiver setups. Environment variables in the yml are the recommended, supported way. For recipient maps, always use proper hash/texthash formats and correct file syntax. actually i’ve removed the custom configuration entirely, the configuration described here, and my mail test worked fine. x86_64 arch detected. Ensuring launcher is up to date Fetching origin Launcher is up-to-date Stopping old container + /usr/bin/docker stop -t 600 mail-receiver mail-receiver release: Pulling from discourse/mail-receiver Digest: sha256:2a0d45bb92a783c846a821e635413764eeadb3441ef6190085545a4[9 digits redacted] Status: Image is up to date for discourse/mail-receiver:release docker.io/discourse/mail-receiver:release ERROR: Can't find Ruby library file or shared library pups cd /pups && /pups/bin/pups --stdin /bin/bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8) sha256:[6 digits redacted]69734d779a95ec83c7103dc2fc04f1d690ebde62[18 digits redacted] [64 character API Key? Redacted] Removing old container + /usr/bin/docker rm mail-receiver mail-receiver + /usr/bin/docker run --shm-size=512m -d --restart=always -e LANG=en_US.UTF-8 -e LC_ALL=en_US.UTF-8 -e LANGUAGE=en_US.UTF-8 -e MAIL_DOMAIN=discourse. MYDOMAINNAME.com -e DISCOURSE_BASE_URL=https:// MYDOMAINNAME.com -e DISCOURSE_API_KEY=[64 digit API key redacted] -e DISCOURSE_API_USERNAME=system -h ubuntu-mail-receiver -e DOCKER_HOST_IP=172.17.0.1 --name mail-receiver -t -p 25:25 -v /var/discourse/shared/mail-receiver/postfix-spool:/var/spool/postfix --mac-address [redacacted mac address] local_discourse/mail-receiver /sbin/boot [64 digit API key? Redacted] root@ubuntu:/var/discourse# ./launcher logs mail-receiver x86_64 arch detected. /bin/bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8) Operating environment: HOSTNAME=ubuntu-mail-receiver LANGUAGE=en_US.UTF-8 MAIL_DOMAIN=discourse.MYDOMAINNAME.com DOCKER_HOST_IP=172.17.0.1 PWD=/ DISCOURSE_BASE_URL=https:// MYDOMAINNAME.com HOME=/root LANG=en_US.UTF-8 TERM=xterm SHLVL=1 DISCOURSE_API_USERNAME=system LC_ALL=en_US.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin INCLUDE_DMARC=true DISCOURSE_API_KEY=[64 digit API key redacted] _=/usr/bin/env Delivering mail sent to discourse. MYDOMAINNAME.com to Discourse Starting OpenDKIM... perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = "en_US.UTF-8", LC_ALL = "en_US.UTF-8", LANG = "en_US.UTF-8" are supported and installed on your system. perl: warning: Falling back to the standard locale ("C"). Adding user `postfix' to group `opendkim' ... Jul 23 13:27:19 usermod[16]: add 'postfix' to group 'opendkim' Jul 23 13:27:19 usermod[16]: add 'postfix' to shadow group 'opendkim'Done. Starting OpenDMARC... perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = "en_US.UTF-8", LC_ALL = "en_US.UTF-8", LANG = "en_US.UTF-8" are supported and installed on your system. perl: warning: Falling back to the standard locale ("C"). Jul 23 13:27:19 opendkim[24]: OpenDKIM Filter v2.11.0 starting (args: -x /etc/opendkim.conf)Adding user `postfix' to group `opendmarc' ... Jul 23 13:27:19 usermod[31]: add 'postfix' to group 'opendmarc' Jul 23 13:27:19 usermod[31]: add 'postfix' to shadow group 'opendmarc'Done. Jul 23 13:27:19 opendmarc[39]: OpenDMARC Filter v1.4.2 starting (args: -c /etc/opendmarc.conf) Jul 23 13:27:19 opendmarc[39]: additional trusted authentication services: (none)postfix: Postfix is using backwards-compatible default settings Jul 23 13:27:19 ubuntu-mail-receiver postfix[51]: Postfix is using backwards-compatible default settings postfix: See http://www.postfix.org/COMPATIBILITY_README.html for details Jul 23 13:27:19 ubuntu-mail-receiver postfix[51]: See http://www.postfix.org/COMPATIBILITY_README.html for details postfix: To disable backwards compatibility use "postconf compatibility_level=3.6" and "postfix reload" Jul 23 13:27:19 ubuntu-mail-receiver postfix[51]: To disable backwards compatibility use "postconf compatibility_level=3.6" and "postfix reload" Starting Postfix Jul 23 13:27:19 ubuntu-mail-receiver postfix/master[1]: daemon started -- version 3.7.11, configuration /etc/postfix Jul 23 13:27:53 ubuntu-mail-receiver postfix/smtpd[122]: connect from mail-il1-f180.google.com[209.85.166.180] Jul 23 13:27:54 policyd-spf[129]: : prepend Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=209.85.166.180; helo=mail-il1-f180.google.com; envelope-from= person@gmail.com; receiver=discourse. MYDOMAINNAME.com Jul 23 13:27:54 ubuntu-mail-receiver postfix/smtpd[122]: BC6D71BF9C8: client=mail-il1-f180.google.com[209.85.166.180] Jul 23 13:27:54 ubuntu-mail-receiver postfix/cleanup[130]: BC6D71BF9C8: message-id= Jul 23 13:27:55 opendkim[24]: BC6D71BF9C8: DKIM verification successful Jul 23 13:27:55 opendkim[24]: BC6D71BF9C8: s=20230601 d=gmail.com a=rsa-sha256 SSL Jul 23 13:27:55 opendmarc[39]: implicit authentication service: ubuntu-mail-receiver.localdomain Jul 23 13:27:55 opendmarc[39]: BC6D71BF9C8: gmail.com passJul 23 13:27:55 ubuntu-mail-receiver postfix/qmgr[120]: BC6D71BF9C8: from= , size=75533, nrcpt=1 (queue active) Jul 23 13:27:55 ubuntu-mail-receiver postfix/smtpd[122]: disconnect from mail-il1-f180.google.com[209.85.166.180] ehlo=1 mail=1 rcpt=1 bdat=2 quit=1 commands=6 Jul 23 13:27:55 receive-mail[133]: Recipient: person.REDACTED@discourse. MYDOMAINNAME.comJul 23 13:27:55 ubuntu-mail-receiver postfix/pipe[132]: BC6D71BF9C8: to= , relay=discourse, delay=1.8, delays=1.6/0.01/0/0.22, dsn=2.0.0, status=sent (delivered via discourse service) Jul 23 13:27:55 ubuntu-mail-receiver postfix/qmgr[120]: BC6D71BF9C8: removed

📬 Repeated Postfix warnings and connections after valid_recipients implementation

Product Support

Ethsim2 (Ethan ) July 23, 2025, 4:31pm 3

reply by email now works on my forum, the legacy valid_recipients thing would have blocked that

Topic		Replies	Views
Email receive issue Bug mail-receiver , fixed	29	1329	April 13, 2026
Configure direct-delivery incoming email for self-hosted sites with Mail-Receiver Self-Hosting email , how-to , advanced-setup , mail-receiver	76	52629	March 27, 2026
Mail-receiver won’t deliver mail to Discourse Self-hosting mail-receiver	16	707	January 26, 2023
Mail-receiver relay access denied Self-hosting mail-receiver	21	2357	January 26, 2025
Customize direct-delivery Postfix configuration Sysadmins how-to , advanced-setup	19	5502	February 14, 2026

📬 Repeated Postfix warnings and connections after valid_recipients implementation

Related topics