# Email receive issue
**URL:** https://meta.discourse.org/t/email-receive-issue/374615
**Category:** Bug
**Tags:** mail-receiver, fixed
**Created:** [July 17, 2025, 9:59am UTC](https://meta.discourse.org/t/email-receive-issue/374615 "2025-07-17T09:59:15Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 9:59am UTC](https://meta.discourse.org/t/email-receive-issue/374615/1 "2025-07-17T09:59:15Z")
Hi Discourse,
after rebuilding #mail-receiver and app this morning, i have been getting the following outcome on email that would have sent previously
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 10:36am UTC](https://meta.discourse.org/t/email-receive-issue/374615/2 "2025-07-17T10:36:45Z")
i’ve tried this setting but still bounces back
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 11:05am UTC](https://meta.discourse.org/t/email-receive-issue/374615/3 "2025-07-17T11:05:24Z")
> [@Ethsim2](#):
>
> 
here are the more recent logs
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 11:06am UTC](https://meta.discourse.org/t/email-receive-issue/374615/4 "2025-07-17T11:06:30Z")
could this be system clock after updating the ubuntu kernel?
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 11:08am UTC](https://meta.discourse.org/t/email-receive-issue/374615/5 "2025-07-17T11:08:40Z")
yes it was an hour behind
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 11:14am UTC](https://meta.discourse.org/t/email-receive-issue/374615/6 "2025-07-17T11:14:56Z")
Right, the test email i sent bounced back with the same error, which is clear in `.\launcher logs mail-receiver`
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 11:44am UTC](https://meta.discourse.org/t/email-receive-issue/374615/7 "2025-07-17T11:44:01Z")
okay so both the mail-receiver container and app container are set to a different time to the host system
* * *
host system - correct time ✅
app container - wrong time ❌
mail-receiver container - wrong time ❌
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 11:59am UTC](https://meta.discourse.org/t/email-receive-issue/374615/8 "2025-07-17T11:59:07Z")
> [@Ethsim2](#):
>
> app container
> [@Ethsim2](#):
>
> mail-receiver container
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 12:09pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/9 "2025-07-17T12:09:03Z")
> [@Ethsim2](#):
>
> app container
From: [Set timezone for Docker container - #2 by OrkoGrayskull](https://meta.discourse.org/t/set-timezone-for-docker-container/244190/2)
* * *
> [@Ethsim2](#):
>
> mail-receiver container
[do as above post](https://meta.discourse.org/t/email-receive-issue/374615/8)
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 12:11pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/10 "2025-07-17T12:11:52Z")
> [@Ethsim2](#):
>
> > [@Ethsim2](#):
> >
> > mail-receiver container
>
> [do as deleted post](https://meta.discourse.org/t/email-receive-issue/374615/8)
well it’s still different, after rebuilding mail-receiver and causing both `-` to go yellow
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 1:27pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/11 "2025-07-17T13:27:52Z")
these were the last emails to get in
---
### Author:  [@supermathie](https://meta.discourse.org/u/supermathie)
#### Post date: [July 17, 2025, 3:27pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/12 "2025-07-17T15:27:50Z")
> [@Ethsim2](#):
>
> okay so both the mail-receiver container and app container are set to a different time to the host system
they appears set to a different time _zone_, which is fine.
Assuming you ran these commands a couple minutes apart, this looks good.
---
### Author:  [@supermathie](https://meta.discourse.org/u/supermathie)
#### Post date: [July 17, 2025, 3:32pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/13 "2025-07-17T15:32:09Z")
It’s impossible to tell from these screenshots what exactly is happening.
What is the inbound address for your forum? (slightly redacted if possible)
What address is it coming from?
What’s happening with mail sent to it?
Please use text of your logs rather than screenshots.
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 3:34pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/14 "2025-07-17T15:34:41Z")
> [@supermathie](#):
>
> What is the inbound address for your forum? (slightly redacted if possible)
[discourse.domain.com](http://discourse.domain.com)
> [@supermathie](#):
>
> What address is it coming from?
- [person@nottingham.ac.uk](mailto:person@nottingham.ac.uk)
- [person@gmail.com](mailto:person@gmail.com)
> [@supermathie](#):
>
> What’s happening with mail sent to it?
it’s connects to mail-receiver but mail-receiver sees the IP as unknown, so bounces it back, the email doesn’t land in the mail-receiver’s queue.
---
### Author:  [@supermathie](https://meta.discourse.org/u/supermathie)
#### Post date: [July 17, 2025, 3:40pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/15 "2025-07-17T15:40:20Z")
> [@Ethsim2](#):
>
> mail-receiver sees the IP as unknown, so bounces it back
I don’t believe this is correct. It’s a warning, not an error.
This screenshot (please make this text) indicates the address `ppyem30@discourse.domain.com` is not accepted - that appears to be the reason for the failure.
I’d look more into the `using backwards-compatible default setting…` line, that seems to be hinting towards the reason.
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 3:49pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/16 "2025-07-17T15:49:10Z")
```plaintext
root@ubuntu:/var/discourse# Jul 17 15:40:20 ubuntu-mail-receiver postfix/master[1]: daemon started -- version 3.7.11, configuration /etc/postfix
Jul 17 15:41:32 ubuntu-mail-receiver postfix/smtpd[122]: connect from btprdrgo001.btinternet.com[65.20.50.131]
Jul 17 15:41:32 ubuntu-mail-receiver postfix/smtpd[122]: disconnect from btprdrgo001.btinternet.com[65.20.50.131] ehlo=1 quit=1 commands=2
Jul 17 15:41:32 ubuntu-mail-receiver postfix/smtpd[122]: connect from btprdrgo001.btinternet.com[65.20.50.6]
Jul 17 15:41:32 ubuntu-mail-receiver postfix/smtpd[122]: NOQUEUE: reject: RCPT from btprdrgo001.btinternet.com[65.20.50.6]: 554 5.7.1 : Recipient address rejected: Mail to this address is not accepted. Check the address and try to send again?; from= to= proto=ESMTP helo=
Jul 17 15:41:32 ubuntu-mail-receiver postfix/smtpd[122]: using backwards-compatible default setting smtpd_relay_before_recipient_restrictions=no to reject recipient "person@discourse.redacted.com" from client "btprdrgo001.btinternet.com[65.20.50.6]"
Jul 17 15:41:32 ubuntu-mail-receiver postfix/smtpd[122]: disconnect from btprdrgo001.btinternet.com[65.20.50.6] ehlo=1 mail=1 rcpt=0/1 data=0/1 rset=1 quit=1 commands=4/6
Jul 17 15:42:49 ubuntu-mail-receiver postfix/smtpd[122]: warning: hostname unassigned.quadranet.com does not resolve to address 198.55.98.78
Jul 17 15:42:49 ubuntu-mail-receiver postfix/smtpd[122]: connect from unknown[198.55.98.78]
Jul 17 15:42:49 ubuntu-mail-receiver postfix/smtpd[122]: disconnect from unknown[198.55.98.78] ehlo=1 auth=0/1 quit=1 commands=2/3
Jul 17 15:43:35 ubuntu-mail-receiver postfix/smtpd[122]: connect from unknown[196.251.92.207]
Jul 17 15:43:36 ubuntu-mail-receiver postfix/smtpd[122]: disconnect from unknown[196.251.92.207] ehlo=1 quit=1 commands=2
```
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 4:04pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/17 "2025-07-17T16:04:51Z")
following
```plaintext
./launcher destroy mail-receiver
```
then following the instructions [here](https://meta.discourse.org/t/configure-direct-delivery-incoming-email-for-self-hosted-sites-with-mail-receiver/49487)
* * *
```plaintext
Delivering mail sent to discourse.DOMAINNAME.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' ...
<86>Jul 17 16:00:00 usermod[17]: add 'postfix' to group 'opendkim'<86>Jul 17 16:00:00 usermod[17]: 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").
<22>Jul 17 16:00:00 opendkim[25]: OpenDKIM Filter v2.11.0 starting (args: -x /etc/opendkim.conf)Adding user `postfix' to group `opendmarc' ...
<86>Jul 17 16:00:00 usermod[32]: add 'postfix' to group 'opendmarc'<86>Jul 17 16:00:00 usermod[32]: add 'postfix' to shadow group 'opendmarc'Done.
<22>Jul 17 16:00:00 opendmarc[40]: OpenDMARC Filter v1.4.2 starting (args: -c /etc/opendmarc.conf)<22>Jul 17 16:00:00 opendmarc[40]: additional trusted authentication services: (none)postfix: Postfix is using backwards-compatible default settings
Jul 17 16:00:00 ubuntu-mail-receiver postfix[52]: Postfix is using backwards-compatible default settings
postfix: See http://www.postfix.org/COMPATIBILITY_README.html for details
Jul 17 16:00:00 ubuntu-mail-receiver postfix[52]: 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 17 16:00:00 ubuntu-mail-receiver postfix[52]: To disable backwards compatibility use "postconf compatibility_level=3.6" and "postfix reload"
Starting Postfix
Jul 17 16:00:00 ubuntu-mail-receiver postfix/master[1]: daemon started -- version 3.7.11, configuration /etc/postfix
Jul 17 16:00:28 ubuntu-mail-receiver postfix/smtpd[123]: connect from mail-ukwestazon11021090.outbound.protection.outlook.com[52.101.100.90]
Jul 17 16:00:28 ubuntu-mail-receiver postfix/smtpd[123]: NOQUEUE: reject: RCPT from mail-ukwestazon11021090.outbound.protection.outlook.com[52.101.100.90]: 554 5.7.1 : Recipient address rejected: Mail to this address is not accepted. Check the address and try to send again?; from= to= proto=ESMTP helo=
Jul 17 16:00:28 ubuntu-mail-receiver postfix/smtpd[123]: using backwards-compatible default setting smtpd_relay_before_recipient_restrictions=no to reject recipient "person@discourse.DOMAINNAME.com" from client "mail-ukwestazon11021090.outbound.protection.outlook.com[52.101.100.90]"
Jul 17 16:00:28 ubuntu-mail-receiver postfix/smtpd[123]: disconnect from mail-ukwestazon11021090.outbound.protection.outlook.com[52.101.100.90] ehlo=1 mail=1 rcpt=0/1 quit=1 commands=3/4
```
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 5:04pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/18 "2025-07-17T17:04:11Z")
```plaintext
Error Details
Error: 554 5.7.1 : Recipient address rejected: Mail to this address is not accepted. Check the address and try to send again?
Message rejected by: ubuntu-mail-receiver.localdomain
```
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 7:09pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/19 "2025-07-17T19:09:59Z")
> [@supermathie](#):
>
> I’d look more into the `using backwards-compatible default setting…` line, that seems to be hinting towards the reason.
i tried [ask.discourse.com](http://ask.discourse.com)
> [@On another topic](https://meta.discourse.org/t/11140/2):
>
> Supermathie is hinting at a feature supported by the Discourse direct-delivery mail-receiver setup, where you can restrict which email addresses your Discourse mail-receiver container will accept incoming mail for. This is accomplished by creating and mounting a “valid\_recipients” file in your mail-receiver’s Docker container configuration, typically in mail-receiver.yml.
>
> Here’s what this means and why you would do it:
>
> * * *
>
> > **What does mount\_recipients file mean?**
> >
> > In your `mail-receiver.yml`, under the `volumes:` section, you add this line:
> >
> > ```plaintext
> > - /var/discourse/shared/mail-receiver/valid_recipients:/etc/postfix/valid_recipients
> >
> > ```
> >
> > This line tells Docker to map the file `/var/discourse/shared/mail-receiver/valid_recipients` from your host system into the container at `/etc/postfix/valid_recipients`.
>
> * * *
>
> > **What is the valid\_recipients file for?**
> >
> > You create the file `/var/discourse/shared/mail-receiver/valid_recipients` yourself and put one valid recipient email address per line. For example:
> >
> > ```plaintext
> > discourse@discourse.yourdomain.com
> > incoming+test@discourse.yourdomain.com
> >
> > ```
> >
> > When you do this, only emails sent to one of these addresses will be accepted by Postfix in the mail-receiver container. All others will be rejected at the SMTP level.
> >
> > * * *
> >
> > ### Why use a valid\_recipients file?
> >
> > - **Security** : Limits who can send into your Discourse by email, reducing possible vector for spam or abuse.
> > - **Control** : You can specify exactly which addresses your forum will “listen” for, which is useful if you have lots of custom email routing or only want to allow specific group or category email addresses.
> > - **Debugging & Filtering** : It helps debug by making sure only intended recipients ever get mail accepted for processing.
>
> * * *
>
> > **Where is this documented/discussed?**
> >
> > The usage is outlined in various places in the Discourse incoming email setup guides on meta, but Supermathie’s post is providing a shortcut for enforcement at the Postfix (SMTP server) level, and not just within Discourse’s internal processing.
> >
> > Here is an overview on setting up direct-delivery, with more detail on customizing Postfix for advanced use:
> >
> > - [Configure direct-delivery incoming email for self-hosted sites with Mail-Receiver](https://meta.discourse.org/t/configure-direct-delivery-incoming-email-for-self-hosted-sites-with-mail-receiver/49487)
> > - [Customising the Postfix configuration of your mail-receiver container](https://meta.discourse.org/t/customising-direct-delivery-postfix-configuration/118759)
> >
> > You can also see specific hints about “valid\_recipients” approaches in this meta answer:
> >
> > - [Email receive issue discussion](https://meta.discourse.org/t/email-receive-issue/374615/15)
>
> * * *
>
> > **Summary:**
> >
> > Supermathie’s hint is a way to strictly control, at the SMTP server level, which addresses Discourse will receive mail for by specifying a list of allowed recipient addresses in a “valid\_recipients” file, mounted into your mail-receiver container. This helps secure and control incoming mail. For more, see the official guides:
> >
> > - [Direct-delivery incoming email setup](https://meta.discourse.org/t/configure-direct-delivery-incoming-email-for-self-hosted-sites-with-mail-receiver/49487)
> > - [Customising Postfix configuration](https://meta.discourse.org/t/customising-direct-delivery-postfix-configuration/118759)
---
### Author:  [@Ethsim2](https://meta.discourse.org/u/Ethsim2)
#### Post date: [July 17, 2025, 8:39pm UTC](https://meta.discourse.org/t/email-receive-issue/374615/21 "2025-07-17T20:39:22Z")
I have followed the steps. One thing that needed clarifying was when i get to the `/var/discourse/shared/mail-receiver/` directory,
should i have written
`nano valid_recipients`
or
`nano valid_recipients.yml`.
* * *
It was a copy+paste job in `mail-reciever.yml` and then another rebuild, corresponding to the below logs
```plaintext
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.DOMAINNAME.com
DOCKER_HOST_IP=172.17.0.1
PWD=/
DISCOURSE_BASE_URL=https://DOMAINNAME.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.DOMAINNAME.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' ...
<86>Jul 17 19:38:44 usermod[16]: add 'postfix' to group 'opendkim'<86>Jul 17 19:38:44 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").
<22>Jul 17 19:38:44 opendkim[24]: OpenDKIM Filter v2.11.0 starting (args: -x /etc/opendkim.conf)Adding user `postfix' to group `opendmarc' ...
<86>Jul 17 19:38:44 usermod[31]: add 'postfix' to group 'opendmarc'<86>Jul 17 19:38:44 usermod[31]: add 'postfix' to shadow group 'opendmarc'Done.
<22>Jul 17 19:38:44 opendmarc[39]: OpenDMARC Filter v1.4.2 starting (args: -c /etc/opendmarc.conf)<22>Jul 17 19:38:44 opendmarc[39]: additional trusted authentication services: (none)postfix: Postfix is using backwards-compatible default settings
Jul 17 19:38:44 ubuntu-mail-receiver postfix[49]: Postfix is using backwards-compatible default settings
postfix: See http://www.postfix.org/COMPATIBILITY_README.html for details
Jul 17 19:38:44 ubuntu-mail-receiver postfix[49]: 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 17 19:38:44 ubuntu-mail-receiver postfix[49]: To disable backwards compatibility use "postconf compatibility_level=3.6" and "postfix reload"
Starting Postfix
Jul 17 19:38:44 ubuntu-mail-receiver postfix/master[1]: daemon started -- version 3.7.11, configuration /etc/postfix
Jul 17 19:39:12 ubuntu-mail-receiver postfix/smtpd[171]: connect from smtp3.nottingham.ac.uk[128.243.44.55]
Jul 17 19:39:12 ubuntu-mail-receiver postfix/smtpd[171]: NOQUEUE: reject: RCPT from smtp3.nottingham.ac.uk[128.243.44.55]: 554 5.7.1 : Recipient address rejected: Mail to this address is not accepted. Check the address and try to send again?; from= to= proto=ESMTP helo=
Jul 17 19:39:12 ubuntu-mail-receiver postfix/smtpd[171]: using backwards-compatible default setting smtpd_relay_before_recipient_restrictions=no to reject recipient "person.xytz@discourse.DOMAINNAME.com" from client "smtp3.nottingham.ac.uk[128.243.44.55]"
Jul 17 19:39:12 ubuntu-mail-receiver postfix/smtpd[171]: disconnect from smtp3.nottingham.ac.uk[128.243.44.55] ehlo=1 mail=1 rcpt=0/1 bdat=0/1 quit=1 commands=3/5
```
* * *
I have custom incoming email addresses for many categories. Does the format need to change to `category+@discourse.DOMAINNAME.com` (for direct posting to a category)?
[Next page](https://meta.discourse.org/t/email-receive-issue/374615.md?page=2)