1 Topic by ketan.aagja

  • ketan.aagja
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Topic: High mail queue

==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.3
- Linux/BSD distribution name and version: CentOS Linux release 7.2.1511 (Core)
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? Yes
- Related log if you're reporting an issue:
====

As far as my new installation of iRedMail is working fine but I am just having max 400 users where I am seeing high mail queue on server. Upon monitoring maillog I can see that mail processing is very slow as compared to earlier. I think POSTSCREEN options set on postfix is taking time in lookups and verification.

Can we turn off POSTSCREEN feature in postfix? Will it speed up mail processing? is it safe? or is there any other options to speed up postfix mail processing?

----

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: High mail queue

*) Postscreen doesn't impact queued emails. It works before-queue.

*) How many CPU cores do you have on this server? and how much RAM?
You may want to tune the server by following this tutorial first:
http://www.iredmail.org/docs/concurrent.processing.html

3 Reply by ketan.aagja

  • ketan.aagja
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Re: High mail queue

Hi Zhang,

I am seeing 24 CPUs on my server

[root@mail ~]# grep processor /proc/cpuinfo
processor       : 0
processor       : 1
processor       : 2
processor       : 3
processor       : 4
processor       : 5
processor       : 6
processor       : 7
processor       : 8
processor       : 9
processor       : 10
processor       : 11
processor       : 12
processor       : 13
processor       : 14
processor       : 15
processor       : 16
processor       : 17
processor       : 18
processor       : 19
processor       : 20
processor       : 21
processor       : 22
processor       : 23

and RAM result is:

[root@mail ~]# free
              total        used        free      shared  buff/cache   available
Mem:       65761072     3164648      533028      771980    62063396    61136300
Swap:      16482300           0    16482300

I have assigned 10 in @max_serves field identical with master.cf file.

But still I am seeing slow performance on mail queue side.

4 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
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Re: High mail queue

Am i right that this server has about 66G RAM? If so, try to increase the max servers to 60, restart both Postfix and amavisd services and try again.

WARNING: Please follow our tutorial strictly, you need to update both Postfix and Amavisd config files.

NOTE: Increasing max servers is just one way to speed up mail flow. We don't know the exact bottleneck yet, so this is just a quick suggestion i can offer. You still need to figure out the bottleneck.

Also, are you using your own DNS server (with cache) on localhost or LAN? a local DNS server will speed up the mail flow too. Reference: http://www.iredmail.org/docs/performance.tuning.html

5 Reply by ketan.aagja

  • ketan.aagja
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Re: High mail queue

Hi Zhang,

Yes server is having 66GB RAM and 24 processors. Is it fine if I increase max server from 10 to 60 as per your suggestions? Does it have to apply processor quantity or RAM amount quantity in postfix and amavisd?

Yes I am using bind as cashing DNS server so not having much DNS queries load on server.

6 Reply by ZhangHuangbin

  • ZhangHuangbin
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Re: High mail queue

ketan.aagja wrote:

Yes server is having 66GB RAM and 24 processors. Is it fine if I increase max server from 10 to 60 as per your suggestions? Does it have to apply processor quantity or RAM amount quantity in postfix and amavisd?

it's fine.

Amavisd + SA + ClamAV need RAM more than CPU.

7 Reply by ketan.aagja

  • ketan.aagja
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Re: High mail queue

Thanks Zhang,

I setup max_servers to 50 and same with master.cf and WOW, now I am seeing the power of postfix the best mail processing engine. Now my email server is processing 30000 emails per hour without delaying anything. Not seeing mail queue more than 3 in pending list.

Thanks a lot for your support.

8 Reply by ZhangHuangbin

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Re: High mail queue

Glad to hear that it works for you. Enjoy. smile