On Fri, Aug 28, 2015 at 04:18:14PM +0100, Gary Stainburn wrote: > The server does sit behind a Fortinet firewall which does do SMTP
> interception. It has it's own built in anti-SPAM and anti-firewall facility.
>
> As the problems I have been experiencing have been from external mail servers
> I have not been able to do any testing. However, if I use the above openssl
> commands from one of my hosted servers, would that re-create the problem?
No, your have to study traversal of tcp packets through firewall,
i.e. traffic between *external* smtp client and your mail server.
The fact that TLS works locally simply confirms that problem is
in some packet filtering on transit.
--
Eugene Berdnikov
