1 Topic by tony_ph

  • tony_ph
  • Member
  • Offline
  • Registered: 2018-02-11
  • Posts: 34

Topic: improper command pipelining EHLO. outlook,thunderbird,bluemail no work

- iRedMail version: 1.6.6 MARIADB edition.
- Deployed with iRedMail Easy or the downloadable installer? Downloadable
- Linux/BSD distribution name and version: Ubuntu 22.04.3 LTS
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): Mysql- MAriadb
- Web server (Apache or Nginx): Ninx
- Manage mail accounts with iRedAdmin-Pro? No
------------------------------------------------------------------------------------------------------------
Hi, i have VM with iredmail since 2020 and always works fine, but since yesterday                               26 feb 2025, without any modifications on the VM it start to reject or timeout requests from outlook, thunderbird and bluemail, all mail clients on mobile or pc but

IMPORTANT: only if not in LAN, indeed i have pc with thunderbird which is in the same subnet of VM and if i edit hosts file of windows and i add 10.0.0.12 smtp.mydomain.it imap.mydomain.it
thunderbird then works fine, but if thunderbird or any other mail client have to pass from my public ip it get this error into logs:
----------------------------------------------------------------------------------------------------------
connect from 93-36-228-152.ip62.fastwebnet.it[93.36.228.152]
improper command pipelining after EHLO from 93-36-228-152.ip62.fastwebnet.it[93.36.228.152]: QUIT\r\n
disconnect from 93-36-228-152.ip62.fastwebnet.it[93.36.228.152] ehlo=1 quit=1 commands=2
connect from 93-36-228-152.ip62.fastwebnet.it[93.36.228.152]
improper command pipelining after EHLO from 93-36-228-152.ip62.fastwebnet.it[93.36.228.152]: QUIT\r\n
disconnect from 93-36-228-152.ip62.fastwebnet.it[93.36.228.152] ehlo=1 quit=1 commands=2
connect from 93-36-228-152.ip62.fastwebnet.it[93.36.228.152]
disconnect from 93-36-228-152.ip62.fastwebnet.it[93.36.228.152] ehlo=1 quit=1 commands=2
connect from 93-36-228-152.ip62.fastwebnet.it[93.36.228.152]
improper command pipelining after EHLO from 93-36-228-152.ip62.fastwebnet.it[93.36.228.152]: QUIT\r\n
disconnect from 93-36-228-152.ip62.fastwebnet.it[93.36.228.152] ehlo=1 quit=1 commands=2
---------------------------------------------------------------------------------------------------------------
It must be something related to the IP address used to comunicate to IredMail.

----

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

2 Reply by TiTo

  • TiTo
  • Member
  • Offline
  • Registered: 2021-08-29
  • Posts: 35

Re: improper command pipelining EHLO. outlook,thunderbird,bluemail no work

We see that IP address 93.36.228.152 sent only two SMTP commands: EHLO and QUIT. This means the client connected, identified itself, and then immediately disconnected without attempting to send an email. Such behavior is highly suspicious and often seen with clients that are on blacklists.

I checked the IP address 93.36.228.152 on mxtoolbox.com, and found that this address is listed on Spamhaus ZEN, Barracuda, and RATS. This clearly indicates that this IP address is associated with spam activities or other malicious behavior. This is the reason why the server is rejecting emails from the address in the log section you sent..

3 Reply by tony_ph

  • tony_ph
  • Member
  • Offline
  • Registered: 2018-02-11
  • Posts: 34

Re: improper command pipelining EHLO. outlook,thunderbird,bluemail no work

I used my mobile 5g hotspot and connected my laptop that's the ip comes from my fastweb mobile service.
Btw i resolved this problem just opening tcp 993 on my firewall and now all mail clients get email without any  problem.
I had to change into mail clients imap from 143 to 993.
But this is very weird cause 143 works for 5 years until yesterday!
What the heck!