I'm using Dspace 1.52. I config Dspace allow only Email address in the
format <username>@gmail.com.
And I config in Dspace.cfg

#### PasswordAuthentication options ####

# Only emails ending in the following domains are allowed to self-register
# Example - example.com domain : @example.com
# Example - MIT domain and all .ac.uk domains: @mit.edu, .ac.uk
authentication.password.domain.valid = @gmail.com

But when I register with E-mail address nghungthanh@gmail.com  Dspace can validate the address
This is the error

User Registration

The e-mail address you entered was invalid. Please try again.

If you've never logged on to DSpace before, please enter your e-mail address in the box below and click "Register".

Any body help me!