1 Topic by idiot_dave

  • idiot_dave
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Topic: New e-mails stopped arriving

==== Required information ====
- iRedMail version (check /etc/iredmail-release):  0.9.5-1
- Linux/BSD distribution name and version:  Ubuntu 16 LTS
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): mysql
- Web server (Apache or Nginx): apache
- Manage mail accounts with iRedAdmin-Pro? no
- Related log if you're reporting an issue:
====

I'm baffled. I'm hoping someone can help me please?  smile

I migrated my users over to iRedmail yesterday. Directed port 25 at the new iRedmail server and new mail started flowing to the user's inboxes fine. This morning however no newer e-mails have arrived. I rebooted the server and the same symptom persists. E-mails to our own domain are working fine, it's just external e-mails never land.

Checking the postmaster logs I got via e-mail.

--------------------- Postfix Begin ------------------------

   24.366M  Bytes accepted                          25,549,511
   15.097M  Bytes sent via SMTP                     15,830,361
   15.148M  Bytes delivered                         15,883,536
   10.674K  Bytes forwarded                             10,930
========   ==================================================

      140   Accepted                                    92.72%
       11   Rejected                                     7.28%
--------   --------------------------------------------------
      151   Total                                      100.00%
========   ==================================================

        8   5xx Reject unknown user                     72.73%
        3   5xx Reject sender address                   27.27%
--------   --------------------------------------------------
       11   Total 5xx Rejects                          100.00%
========   ==================================================

      137   4xx Reject recipient address               100.00%
--------   --------------------------------------------------
      137   Total 4xx Rejects                          100.00%
========   ==================================================

      268   Connections   
        1   Connections lost (inbound)
      268   Disconnections
      144   Removed from queue
       72   Delivered
       72   Sent via SMTP
        3   Forwarded
        4   Resent
      470   Postscreen

        8   Timeouts (inbound)
      188   TLS connections (server) 


---------------------- Postfix End -------------------------

For now I've pointed back to to Exchange. But I'm confused as to what broke over night.

Thanks

Dave

----

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

2 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
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Re: New e-mails stopped arriving

You should check Postfix log file first to figure out why it didn't accept new emails. If no log at all, that means there's something wrong with your firewall rule because the mail traffic didn't arrive at new server at all.

3 Reply by idiot_dave

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Re: New e-mails stopped arriving

ZhangHuangbin wrote:

You should check Postfix log file first to figure out why it didn't accept new emails. If no log at all, that means there's something wrong with your firewall rule because the mail traffic didn't arrive at new server at all.

Thanks for your reply. I'll take a look at that now.

4 Reply by idiot_dave (edited by idiot_dave 2016-12-08 23:38:27)

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Re: New e-mails stopped arriving

Looking at the logs the last e-mail sent from the outside world was at 17:49 which was a reject due to  unknown user, which is correct.

The next entry in the log is the scheduled tasks overnight for the postmaster logs. After that it's outgoing and internal e-mails only.

I can telnet from inside my network to the server and get as far as what I presume is the greylisting soft reject. So it doesn't seem to be a server firewall issue for port 25.

Having switched my firewall redirection of port 25 rule from the new server's IP back to the old server's IP the mail is flowing to the old exchange server correctly. So the rule seems correct.

I'm totally baffled. sad

5 Reply by ZhangHuangbin

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Re: New e-mails stopped arriving

Don't panic, log is your (best) friend.

You got "unknown user" error, but which user? Does it really exist on your server? Did you try to send/receive locally with a webmail/MUA or with command line tool? Verify it first.

6 Reply by idiot_dave (edited by idiot_dave 2016-12-09 00:28:10)

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Re: New e-mails stopped arriving

Thanks again for your help. The user 'kristina' @ our domain name doesn't exist as a user, attempting to e-mail internally is a 5.1.1 error, which is correct, that should be rejected. I think that's a red herring though, it just happens to be one of the last things in the logs. 17:52. The item in the logs isn't till 03:30, which I presume is the maintenance tasks completing and postmaster getting an e-mail.

Just a thought, having looked at the mail logs, all our port 25 traffic is coming from the same IP, which is that of our cloud based spam filter. Could the server have been clever enough to block that IP?

Do I just need to whitelist our cloud service IPs? If so, how do I do that lol smile

*edit* and if I was, would services like greylisting and scanning be useless?

7 Reply by ZhangHuangbin

  • ZhangHuangbin
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Re: New e-mails stopped arriving

idiot_dave wrote:

Just a thought, having looked at the mail logs, all our port 25 traffic is coming from the same IP, which is that of our cloud based spam filter. Could the server have been clever enough to block that IP?

*) add this IP in Fail2ban for whitelisting (/etc/fail2ban/jail.local, so that it won't block it.
*) Add it in Postfix "mynetworks ="
*) Add it in /opt/iredapd/settings.py, 'MYNETWORKS =' (this parameter doesn't present by default, please add it manually and find the default settings and syntax in /opt/iredapd/libs/default_settings.py).

idiot_dave wrote:

*edit* and if I was, would services like greylisting and scanning be useless?

I expect the greylisting done on your spam filter server, isn't it? And maybe you'd like to completely disable spam/virus scanning on your iRedMail server because all jobs will be done on spam filter server?

8 Reply by idiot_dave

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Re: New e-mails stopped arriving

Your instructions were brilliant. E-mail has been flowing over the weekend without problems. I think you are correct, I probably don't need the filtering on the iRedmail side if it's being done in the cloud, I guess it would double the time added to a greylisted e-mail since it's being rejected twice.

Thanks again.

Dave