1 Topic by jagter6

  • jagter6
  • Member
  • Offline
  • Registered: 2013-12-04
  • Posts: 27

Topic: Slow SMTP Connections

==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.96
- Linux/BSD distribution name and version: Ubuntu 16.04 LTS
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx):Nginx
- Manage mail accounts with iRedAdmin-Pro?Yes
- Related log if you're reporting an issue:
====

When I run the SMPT test from then website mxtoolbox.com against my one iRedMail server, It records connection and transaction times of 8 - 15 seconds.

When I run the same test against iRedmail servers running older versions, then time are around 0.5 - 1.5 seconds.

The two mail servers are VMware machines running on the same host

Any ideas?

Regards

----

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
  • iRedMail Developers
  • Offline
  • Registered: 2009-05-06
  • Posts: 30,770

Re: Slow SMTP Connections

Did you see word ‘postscreen’ in Postfix log file? If yes, this delay is caused by postscreen, used to delay spammers. Answer in short: works as designed.

For more details about postscreen, please read the official document below:
http://www.postfix.org/POSTSCREEN_README.html

And i don’t think there’s any tuning required, because if one client passed the postscreen tests, postscreen will temporarily whitelist this client (IP address).