Relay server - SMTP help needed

[Huggiesbear78]

Hello all, I hope you are all well. Just trying to get some support to setup a relay SMTP server. The reason I want to setup voicemail to email from my Mitel MN3300 CXi.

Now this needs to be a relay as the system doesn't give the option to add authentication, just an email address the .wav file gets sent to. I have win2008 R2 with IIS6.

Which is the best mail provider to use? At the mo I am trying g-mail. Do I need FQDN with say Go Daddy as mine is just a local DN. I have followed many guides to program the SMTP like the access

http://www.vsysad.com/2014/01/configure-iis-smtp-server-to-use-gmail-to-forward-messages/

 

Just can't get it working and its doing my head in. Can any recommend a free email relay app or some advice please [emoji3][emoji3][emoji3]