1 Topic by tplancon

  • tplancon
  • Member
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  • Registered: 2018-06-14
  • Posts: 34

Topic: My email server not responding to incoming email

==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.8
- Deployed with iRedMail Easy or the downloadable installer? Download
- Linux/BSD distribution name and version: CentOS 7.6.1810
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): PGSQL
- Web server (Apache or Nginx): Hginx
- Manage mail accounts with iRedAdmin-Pro? NO
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
Hello,

We use an email filtering gateway by Sophos to handle quarantine and blacklisting offsite. Our MX records point to the gateway, then after being checked and filtered it is forwarded to our server. Every so often, about once every 1 to 2 weeks, the Sophos gateway starts showing smtp 441 errors, "server not responding", as t tries to forward emails to us. The emails end up in a delivery queue on Sophos where it retries, sometimes for days, with the same error.

I've checked the maillog on our email server and see no errors such as reject or timeout for the emails trying to be forwarded from Sophos. I don't even see an attempt at connection at the time Sophos is attempting to deliver. I can see the emails in the delivery queue on Sophos through their management console. Not all emails get a 441 error, most go through fine, and this doesn't happen everyday, just every few days. But the ones that get stuck in the queue stay there for a long time repeating the 441 error.

Any thoughts as to what could be going on and possibly fixing it are greatly appreciated. Sophos support just says "your server is not responding, nothing we can do".

Thanks much!

----

Spider Email Archiver: On-Premises, lightweight email archiving software developed by iRedMail team. Supports Amazon S3 compatible storage and custom branding.

2 Reply by breal4all (edited by breal4all 2020-08-08 08:22:16)

  • breal4all
  • Member
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  • Registered: 2020-08-08
  • Posts: 8

Re: My email server not responding to incoming email

So did you check the postfix logs ? Do you have disable Amavisd + ClamAV + SpamAssassin , as you have a front end defense Sophos , so it is not because of those systems giving troubles ? Did you check those logs as well ?

Do you monitor your network and the mailserver ?  So  in case there are no drop of packages, a server not responding
can also be a disconnect,  network failure


tplancon wrote:

==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.8
- Deployed with iRedMail Easy or the downloadable installer? Download
- Linux/BSD distribution name and version: CentOS 7.6.1810
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): PGSQL
- Web server (Apache or Nginx): Hginx
- Manage mail accounts with iRedAdmin-Pro? NO
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
Hello,

We use an email filtering gateway by Sophos to handle quarantine and blacklisting offsite. Our MX records point to the gateway, then after being checked and filtered it is forwarded to our server. Every so often, about once every 1 to 2 weeks, the Sophos gateway starts showing smtp 441 errors, "server not responding", as t tries to forward emails to us. The emails end up in a delivery queue on Sophos where it retries, sometimes for days, with the same error.

I've checked the maillog on our email server and see no errors such as reject or timeout for the emails trying to be forwarded from Sophos. I don't even see an attempt at connection at the time Sophos is attempting to deliver. I can see the emails in the delivery queue on Sophos through their management console. Not all emails get a 441 error, most go through fine, and this doesn't happen everyday, just every few days. But the ones that get stuck in the queue stay there for a long time repeating the 441 error.

Any thoughts as to what could be going on and possibly fixing it are greatly appreciated. Sophos support just says "your server is not responding, nothing we can do".

Thanks much!

3 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
  • iRedMail Developers
  • Offline
  • Registered: 2009-05-06
  • Posts: 31,074

Re: My email server not responding to incoming email

- Disable "fail2ban" service temporarily and try again.
- Check Postfix log file (/var/log/maillog) and extract related errors.

4 Reply by breal4all

  • breal4all
  • Member
  • Offline
  • Registered: 2020-08-08
  • Posts: 8

Re: My email server not responding to incoming email

breal4all wrote:

So did you check the postfix logs ? Do you have disable Amavisd + ClamAV + SpamAssassin , as you have a front end defense Sophos , so it is not because of those systems giving troubles ? Did you check those logs as well ?

Do you monitor your network and the mailserver ?  So  in case there are no drop of packages, a server not responding
can also be a disconnect,  network failure


tplancon wrote:

==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.8
- Deployed with iRedMail Easy or the downloadable installer? Download
- Linux/BSD distribution name and version: CentOS 7.6.1810
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): PGSQL
- Web server (Apache or Nginx): Hginx
- Manage mail accounts with iRedAdmin-Pro? NO
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
Hello,

We use an email filtering gateway by Sophos to handle quarantine and blacklisting offsite. Our MX records point to the gateway, then after being checked and filtered it is forwarded to our server. Every so often, about once every 1 to 2 weeks, the Sophos gateway starts showing smtp 441 errors, "server not responding", as t tries to forward emails to us. The emails end up in a delivery queue on Sophos where it retries, sometimes for days, with the same error.

I've checked the maillog on our email server and see no errors such as reject or timeout for the emails trying to be forwarded from Sophos. I don't even see an attempt at connection at the time Sophos is attempting to deliver. I can see the emails in the delivery queue on Sophos through their management console. Not all emails get a 441 error, most go through fine, and this doesn't happen everyday, just every few days. But the ones that get stuck in the queue stay there for a long time repeating the 441 error.

Any thoughts as to what could be going on and possibly fixing it are greatly appreciated. Sophos support just says "your server is not responding, nothing we can do".

Thanks much!

How do you forward  the mail from Sophos   with a DNS name are IP ? Any progress ? If your DNS at the Sophos box dont resolve ok then also this can be a problem.   Try  direct IP4 adress.  Is  the mailserver overloaded ? CPU and ram status ? can you find relevant info in netdata (monitor) ?

Turn off all services that you dont need, what can causing problems.  Or better setup Nagios to monitor network and postfix. So you can find some trends.     Sent me a mail if i have time :-)    maybe i can help out:   

breal4all  AT gmail.com