I hope this is the correct place to post this. Im currently running MS Exchange for a couple of domains and a few users. I only have access to one public IP address and I was hoping to try out Zimbra with a test domain or 2 to ensure I can cope with it before switching everthing over form exchange.
I have setup my Zimbra Server and portmapped a random port of the firewall public IP address to the SMTP port of the internal Zimbra server. I then used DNSmade easy which provides a SMTP port mapping service (they provide port 25 and resend to whichever port you wish). Emails sent externally to the Zimbra email address get through but get stuck in the deferred queue. Emails sent from Zimbra get delivered perfectly. The deferred messages have the error: 'connection to externalIP: connection refused'.
I realise my setup is far from ideal but I have 2 questions:
1) Is there something I can tweak to try it out but not use the port 25 for SMTP (so it doesnt interfere with Exchange until I swap)?
2)If I was to portmap the external IP port 25 to the Zimbra port 25, would everything start work (in theory!)?
If you've got this far, thanks for reading I hope it makes sense!!
Any thoughts / comments /further question warmly welcome.