Hey Travis,

>I'm having trouble sending email from my ASP.NET web pages. As long as I use an email address from my domain as the sender and the receiver, everything works fine. However, if I try to include an email address outside of my domain in either the "From" or the "To" section, I get an error saying "The server rejected one or more addresses. The server response was: 505 not local host domainnamehere, not a gateway.

I'm guessing that your email server does not allow addresses outside your email server domain to be the "From" address, unless you change it to allow outside addresses to send using your mail server, which opens up your server for all kinds of foolishness.

The System.Web.Mail.MailMessage obviously does not include a separate "ReplyTo" property, which could perhaps let you get around the problem by including your address as the From and the user's address as Reply-To, meaning that you could then reply directly to them.

Maybe you can just use your address for From and put their address in the CC, then when you reply to them, just Reply All and remove your address (not elegant, but it works).

Alternatively, you might check out the SMTP components from people like /n Software (www.nsoftware.com) or Dart (www.dart.com) to see if they support your needs better.