I have a working install of Zimbra OSE. I am trying to allow my WHMCS (billing script) connect and send out emails via SMTP from and external server. I have tried every combination of ports and security type and every connection is refused. I have search all over the internet and tried to search on the forums for a solutions before posting here but I can't find one.

Please help!

Edit: Screwed up sorry. Please move to correct forum. SORRY