We currently have 6+ web application servers all doing direct delivery from IIS ( SMTP service ).
Every couple of months we have to clear ourselves from block lists and having no visibility of emails getting set is a pain.
Whilst googling I found some organisations that supply a mail forwarding / relay service see:
Does any one have any experiance of using a mail server to send messages that is outside their hosting environment.
My convern is that over time we have had to set up sticky addresses to our servers, reverse DNS etc. to get mail to work therefore what what would we need to do to get emails accepted by clients using an external mail server?
I guess what I'm asking is how would the recipients mail server know to trust the email connection though the hosted service when it originated from our data centre?
Many thanks, Jason