Multi Server SMTP Auth Problem

[indrasa]

Hi guys, I installed Zimbra 6.0.6 in multi server architecture, 1 Mailbox and 2 MTAs all installations are working perfectly, but I got problem when authenticating smtp from external network (public network).

I tested using telnet from public network (202.x.x.x) resulted below:

[root@mx ~]$ telnet mx.example.com 25
Trying xxx.xxx.xxx.xxx...
Connected to mx.example.com.
Escape character is '^]'.
220 SMTP service ready
EHLO mx.example.com
250-Requested mail action okay, completed
250-SIZE 3072000
250 8BITMIME

<-- WHERE are the authentication methods?

But when i telnet from local networks 192.168.0.x

[root@mx ~]$ telnet mx.example.com 25
Trying xxx.xxx.xxx.xxx...
Connected to mx.example.com.
Escape character is '^]'.
220 mx.example.com ESMTP Postfix
EHLO mx.example.com
250-mx.example.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-AUTH LOGIN PLAIN
250-AUTH=LOGIN PLAIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN

The authentication method appeared! What am I missing for the zimbra configuration? I followed everything in the WIKI and docs for the smtp auth.

All emails both incoming and outgoing are working perfectly "except" sending email from outlook using smtp authentication

Using Ms. Outlook error resulted:

Send test e-mail message: None of the authentication methods supported by this client are supported by your server.

I know it's caused by no authentication method supported by the server.

Any help? Thanks before!