==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.8
- Deployed with iRedMail Easy or the downloadable installer?: Downloadable
- Linux/BSD distribution name and version: CentOS 7.8
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL (MariaDB)
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro?: Yes
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Hi Zhang,

Inbound emails from EIG servers (unifiedlayer.com) are rejected with the following error:

554 5.7.1 <1-2-3-4.unifiedlayer.com>: Helo command rejected: ACCESS DENIED. Your email was rejected because the sending mail server appears to be on a dynamic IP address that should not be doing direct mail delivery (1-2-3-4)

(Of course, the IP address is masked.)

There are these existing lines in /etc/postfix/helo_access.pcre, about half way down:

# bypass some HELOs which contains IP address
/^o\d{1,3}-\d{1,3}-\d{1,3}-\d{1,3}\.outbound-mail\.sendgrid\.net$/ DUNNO

So in order to accept emails from EIG/unifiedlayer.com servers I added this line immediately below the above two lines and restarted Postfix:

/^o\d{1,3}-\d{1,3}-\d{1,3}-\d{1,3}\.unifiedlayer\.com$/ DUNNO

However, the emails are still bounced with the same error message.

Do you have a suggestion for what is still causing the sending server to be blocked?

Thank-you.

Craig