Wrong HELO on Webmail Only??

[cyberdeath]

Hello everyone,

I am facing a very strange issue that I cannot seem to resolve on my own (still trying, though).

When I send an e-mail from Zimbra Webmail, the HELO name is incorrect because it uses the mail server name and not the domain name it is being sent from.

Received: from mail.servername.com (mail.domain.com [xxx.xxx.xxx.12])

However, if I manually send mail through port 25 using another mail client (Outlook, Thunderbird, Windows Mail, etc...) it works just fine:

Received: from MyComputerName (ip.reverse.internet.my.domain.net [xxx.xxx.xxx.xxx])

When I look at the zimbra.log file, I can see the issue is with the HELO command because everything else is working correctly.

zimbra.log (Wrong)

Dec 22 21:13:55 mail postfix/smtp[19133]: > 127.0.0.1[127.0.0.1]:10022: XFORWARD NAME=mail.domain.com ADDR=xxx.xxx.xxx.12 PORT=59139
Dec 22 21:13:55 mail postfix/smtp[19133]: > 127.0.0.1[127.0.0.1]:10022: XFORWARD PROTO=ESMTP HELO=mail.servername.com SOURCE=LOCAL

zimbra.log (Right)

Dec 22 21:32:54 mail postfix/smtp[32206]: > 127.0.0.1[127.0.0.1]:10022: XFORWARD NAME=ip.reverse.internet.my.domain.net ADDR=xxx.xxx.xxx.xxx PORT=50625
Dec 22 21:32:54 mail postfix/smtp[32206]: > 127.0.0.1[127.0.0.1]:10022: XFORWARD PROTO=ESMTP HELO=MyComputerName SOURCE=LOCAL

Does anyone have any idea how I can change the HELO name for webmail? Ideally, I would like it to change dynamically depending on what domain the mail is being sent out on.

Any assistance/guidance/help is greatly appreciated.