A problem that we occasionally see occuring
with SMTP is that it is blocked by the customer's local ISP because the
reply address contains a domain name that is not hosted in their
If this is the case, then your ISP joins a short list of ISPs who do this (Verizon, MSN, Rogers, to name a few).
The primary indications of this are represented by the error "We do not
relay" that you are receiving and the fact that it is happening with all
Most ISPs relay messages through their SMTP servers by the source IP
address. Therefore, as their customer, they allow sending of mail
through their servers from the IP addresses in their network. And you
would have a valid IP as you are their customer and pay them for
internet and mail services to and from your workstation. This does not
appear to be the case with your ISP.
The only recourse you have is to complain to your ISP. If they will not
fix this problem, then you can subscribe to the Alentus SMTP "Auth"
service for only $4.95 per month. For the single monthly fee, anyone in
your organization from your domain name, can send out using our SMTP
If you would like this set up, please request it through the Alentus
Support Center, by Submitting a Ticket to Sales & Ordering.
You may specify a username and password that your users will put into
their Outlook to authenticate automatically into our outgoing SMTP
server. This will have no effect on how they currently receive email.