I'm having a weird problem with site registration on DNN 5.6.0:

We are pleased to advise that you have been added as a Registered User to Twin City Track Club - Winston Salem, NC. Please read the following information carefully and be sure to save this message in a safe location for future reference.

Portal Website Address: twincitytc.org
Username: <username>
Password: <password>
Verification Code: *******

You can use the following link to complete your verified registration:

http://twincitytc.org/default.aspx?ctl=Login&username=<username>&verificationcode=*******



I've blanked out the username and password, but the ***** in the verification code is as-is from the email. ANyone know what causes this and how to fix it?

I have figured out what the error was to my own question similar to yours, In the Host SMT Setting under Security, I typed in localhost instead of the Mail Server name you're using on the server. Authenticaton I left it as Anonymous...
Once done that, an email will then be send to the designated emailbox at Registration with the username and password entered.

it worked for me, hope this works for you too.