Issue smtp.helo is not correct

[itoop]

Hallo,

on plesk 17.8.11 in the Server-Wide Mail Settings I set as Outgoing mail mode "Send from domain IP adresses". At Server Settings I set als Full hostname a FQDN. My Reverse-DNS-entry is correct (testet by dnsstuff.com; Reverse DNS entry is green/pass as well as all tests for mail).
My problem is, that nevertheless the smtp.helo is not set correctly: If I write an email from roundcube to my gmail-adresse, I can see, that "smtp.helo=webmail.andre-hohmann.net" is set and not the FQDN! If I write an email from my iPhone-mail-app, it is set "smtp.helo=[192.168.179.23]", so my internal network IP and not the FQDN!
Additionally one Mailserver of a company doesn't accept my mails (Diagnostic-Code: smtp; 554).

What can I do?

 

[IgorG]

Do you have Postfix or Qmail MTA?

 

[itoop]

Postfix.

 

[IgorG]

What is output of commands

# postconf | grep ^myhostname
# cat /etc/hostname

?

 

[itoop]

$ postconf | grep ^myhostname
myhostname = mail.itoop.de

$ cat /etc/hostname
mail.itoop.de