550 Bad HELO - Host impersonating domain name

[TestUser123]

Hello,

i have 2 servers

server A is www

server B is email...

i have multiple prestashops with different versions... all are working perfect... but 1

I have 1.7.7.2 version and it stopped sending emails....

i have checked and edited spf record.... but still emails are not send...

what could I do to fix this?
when I go to 
CONFIGURE /Advanced Parameters /E. mail
and try and send a test email  get error:
 

Error: Please check your configuration

Expected response code 250 but got code "550", with message "550 Bad HELO - Host impersonating domain name

on email server in exim log I see this

ž2023-08-01 13:49:29 H=server.shotname (domain.com) [www-server-ip] rejected EHLO or HELO domain.com: Bad HELO - Host impersonating domain name [domain.com]

Ideas!?