======== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.6 MYSQL edition.
- Linux/BSD distribution name and version: Ubuntu 16.04.2 LTS
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? no
- Related log if you're reporting an issue:
====

I'm the lab manager that supporting some developers that are creating a new product for my company.  One of the components of this product is to send email notifications.  They want to send Authenticated, and non-authenticated.  I don't know if they even know that SSL exists.

I setup an iRedMail server to serve as the test target.  The "real world" smtp server so to speak.

Of course I'm having issues.

But at this point, I'm can't determine if it's the client my developers are coding, or the way I configured the server.

So when I send Unauthenticated (port 25) to a local user, it works.   (i'd like to figure out how to forward to our real mail-server, but that's another day)

When I enable authentication (On the mail client and use port 587), it fails

Here's the mail.log for the connection

Apr 10 15:36:02 iredmail postfix/submission/smtpd[2159]: connect from sti-apm.nest.anr.ms.yyy.com[10.30.35.21]
Apr 10 15:36:02 iredmail postfix/submission/smtpd[2159]: improper command pipelining after HELO from sti-apm.nest.anr.ms.yyy.com[10.30.35.21]: \r\n
Apr 10 15:36:02 iredmail postfix/submission/smtpd[2159]: lost connection after HELO from sti-apm.nest.anr.ms.yyy.com[10.30.35.21]
Apr 10 15:36:02 iredmail postfix/submission/smtpd[2159]: disconnect from sti-apm.nest.anr.ms.yyy.com[10.30.35.21] helo=1 ehlo=1 auth=0/1 commands=2/3

attaching the main.cf

I'm not sure where to go from here.