Steps to reproduce the issue

1. Create a user account on a Joomla website.
2. Use a user name as "Cristal wants to see you in 9 hours http://www .connecticut-weddings.com/redirect.asp?URL=http://project1200995 .tilda.ws,"

Expected result

Error about user name

Actual result

Activation e-mail is send to new user as:

"Hello Cristal wants to see you in 9 hours http://www. connecticut-weddings.com/redirect.asp?URL=http://project1200995. tilda.ws,

Thank you for your registration..."

System information (as much as possible)

Joomla 3.9.4

Additional comments

User name should be checked against URI content and fail