1 Topic by hyde (edited by hyde 2017-10-07 04:22:06)

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Topic: Issue with smtp and OSX clients

==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.7 PGSQL edition.

- Linux/BSD distribution name and version: debian 9.1
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): PGSQL
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? nope
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Hi,

I installed an iredmail solution on a brand new server and everything works well ... except from time to time some clients got some error messages when trying to send emails.

They get some messages about ports expired or timed out connection... not sure about the message and cant see anything in the logs about that.

They got also that message :

Cannot connect to SMTP server xxx.xxx.xxx.xxx (xxx.xxx.xxx.xxx:587), connect error 10060.

I had some little issues due to max connections on pgsql and about its shared buffers but a little tweak on the config and everything was ok until these messages ...

If you have any idea because i dont know what to check else ...

----

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2 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
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Re: Issue with smtp and OSX clients

- Any related error in Dovecot log file when this issue occur?
- If you have many IMAP clients, try to increase limit of max concurrent imap sessions in Dovecot config file.

3 Reply by hyde

  • hyde
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Re: Issue with smtp and OSX clients

ZhangHuangbin wrote:

- Any related error in Dovecot log file when this issue occur?
- If you have many IMAP clients, try to increase limit of max concurrent imap sessions in Dovecot config file.


The only errors I have are these one :

Oct  7 16:03:10 mail dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=37.70.164.145, lip=xxx.xxx.xxx.xxx, TLS handshaking: SSL_accept() failed: error:1408F10B:SSL routines:ssl3_get_record:wrong version number, session=<3MvqavVaEdAlRqSR>

but not so many ...

I have 60 dovecot processes and the max_userip_connections is 60 too ... dunno if I should increase that setting because it's not the same error that we get...

4 Reply by ZhangHuangbin

  • ZhangHuangbin
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Re: Issue with smtp and OSX clients

hyde wrote:

I have 60 dovecot processes and the max_userip_connections is 60 too ... dunno if I should increase that setting because it's not the same error that we get...

max_userip_connections is not "limit of max concurrent imap sessions".

Is your server very busy? especially IMAP service.

5 Reply by hyde

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Re: Issue with smtp and OSX clients

not really a busy one :

Per-Day Traffic Summary
    date          received  delivered   deferred    bounced     rejected
    --------------------------------------------------------------------
    Oct  1 2017        69        292        300          1         49
    Oct  2 2017       193        710        347          4         28
    Oct  3 2017       212        974        371          1          4
    Oct  4 2017       184        647        193          0         22
    Oct  5 2017       221        831          1          3         57
    Oct  6 2017       207        773          1          6        120
    Oct  7 2017        97        336          0          0        131
    Oct  8 2017        37         84          0          0         52

6 Reply by ZhangHuangbin

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Re: Issue with smtp and OSX clients

It might be caused by fail2ban.
next time when same issue occur, try to check whether the client IP is blocked in iptables firewall:

iptables -L -n

If yes, it's caused by fail2ban. You can unblock the IP with script shipped in iRedMail-0.9.7: tools/fail2ban_unban_ip.sh.

bash fail2ban_unban_ip.sh xx.xx.xx.xx