Since we're having problems with SMTP restrictions on our shared hosting account, I decided to try using an SMTP service.  So I got an account on AuthSTMP and configured it.  Then I went to our sandbox DNN system, changed SMTP settings in Host Settings, saved it, and did a test email.  It worked!

Then I went to the production site and made the identical changes, and got an error trying to send email.  The two sites are identical except for the domain. The sandbox site was created by installing a clone of the production site.

I'm stumped! Why does this work on the test site and not the production site?

Sandbox site:
Host email: admin@domainx.org
SMTP Server and port: mail.authsmtp.com:2525
SMTP Authentication: Basic
SMTP Username and password are identical.

William

I'm not really sure what the problem was, but I did get it to work finally.  I changed the settings for SMTP server, login, and password to the sandbox's smtp server first (they're on the same host PC), then when that tested ok I changed them again to use AuthSMTP.  This time it worked.  I'll take success over knowledge in this case. :-)

By the way, AuthSMTP is great. Cheap to use, easy to set up, and you can see a log of outbound email and any errors.  No more worries about SMTP restrictions on the host.