Secure IIS SMTP Server – Configure with Username and Password

We tried going this route too, but relaying email can be quite difficult. After struggling with the Windows SMTP server for a couple months, we gave up and created an SMTP Proxy which we uploaded to CodePlex. You can use it for free and it is much simpler to use and maintain.

It isn't uncommon for applications to only support a server name and nothing else. These apps just don't support authenticating before they send. Nothing about that requires you to run your own mail server locally - it just means you need to list a mail server that will accept the mail without first authenticating. There are 2 ways to achieve that:

1. If the name of the mail server you give it is the mail server that hosts your mailboxes (Verizon, in your case) and the UPS alerts are only going to your mailboxes, you can list that server without even asking Verizon first. Their system will always receive mail for your email addresses so that will work.

2. If you supply a different mail server that isn't configured to host mail for your email addresses, that server will usually reject the mail unless you authenticate first. BUT, you can often convince the company to allow a specific IP address to relay through them. It sounds like this would be the likely option for the local company you use. They may or may not offer that service. Note that you would be able to give them a specific external IP address that all of the mail would be coming from which could get tricky if that box the UPS software runs on isn't already connected to the internet.

Really, #1 is by far the easiest solution. Good luck!