Issue No more mail received when activating Greylisting

[Chrisg]

Server operating system version

Debian 12.11

Plesk version and microupdate number

18.0.69 #3

Following the migration of an Obsidian 18.0.44 server to a new Obsidian 18.0.69 server, we are encountering a problem receiving mail when the function:
"Enable Greylisting spam protection for all accounts under this domain"
is activated.

The error message is:

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

SMTP error from remote mail server after pipelined DATA:
host XXX.XXX.XXX.XXX [XXX.XXX.XXX.XXX]: 550 5.7.1 Command rejected

If disabled, mail is received.
This option was enabled on the source server and everything worked fine.

How can I activate it again and receive e-mails correctly?

Thx.

 

[Sebahat.hadzhi]

Hello, @Chrisg . As far as I am aware, no changes were performed on the method and logic of greylisting. Does the issue occur for a particular sender only? If yes, what you can do is examine the sender IP and domain with a tool like MXToolbox. What else I might suggest is to try adding the sender address to the whitelist and check the current settings:

• https://support.plesk.com/hc/en-us/articles/12377800496919-How-to-configure-Greylisting

 

[Chrisg]

Thank you.

The problem occurs regardless of the sender.
It worked correctly on the previous server when gmail.com domains for example sent messages to domains hosted on Plesk, whereas now an error message is returned to the sender.
To receive the mails, we had to disable greylisting.
I'll have a look at the settings indicated.

Do we need to initialize anything for greylisting to work, I don't remember doing this on the previous server.