by Mihai Bojonca.
I think i solved the problem at list partly.
It was the hard way.
I changed smtp servers and suddenly my IP was landing in CBL due to
"At the time of removal, this was the explanation for this listing:
This IP address is HELO'ing as "localhost.localdomain" which violates the relevant standards (specifically: RFC5321)."
I found this document on their website.
Looks like sendmail was not picking up automatically the domain name so i had to change the sendmail.mc and compile a new sendmail.cf also indicating the domain name in
/etc/mail/local-host-names