Our e-mail path is as follows:  Outgoing - IMail Server 2006 uses a Tumbleweed server as the gateway.  IF the e-mail is destined for our insurance company, the Tumbleweed server will send it via TLS.  If it is destined for any other domain, it goes normal.  IMail server does not go directly to the internet.

Incoming - MX record points to 3rd party SPAM and Virus detection.  After cleaning, mail is sent to Tumbleweed server.  If from insurance company, mail is unencrypted by Tumbleweed and sent to IMail server.  If from any other host, it is sent directly to IMail server.

We are changing our mail to go through Postini.  This means that a TLS connection needs to be set up between IMail server and Postini (we are doing away with the Tumbleweed server).  Outgoing mail will travel to Postini and then sent to final domain.  If to insurance company, it will be sent from Postini via TLS.  All mail from IMail to Postini will be TLS.

Incoming - MX record will point to Postini.  Postini will do SPAM and Virus checks, then send to IMail server directly via IP address.

Incoming from insurance company will go directly to IMail Server via IP address.

Looks easy on paper.

Followed Ipswitch instructions on creating SSL Certificate and installed certificate as per instructions.

Went to IMail admin and checked box for TLS in SMTP properties.  Stopped/started SMTP and Que Manager.

Had insurance company send test message to IMail server (required TLS from their end).  They received error - unable to establish TLS connection.

No firewall issues, as same type of traffic was flowing in with no problem to Tumbleweed server.

Contacted Ipswitch Tech Support.  I asked if certificate had to be installed/activated anywhere for TLS.  He said no. 

The problem is that TLS is not working.  What step have I left out on this?  Does SSL have to be checked?  I created a certificate.  I installed it via their instructions but how does it relate to the TLS? 

Nothing against the support dude, but I don't believe he was quite understanding where I was coming from and/or did not understand the concept of TLS between servers.

Any help would be appreciated.