Mail2web.com ignoring DWA Access Restriction

I have allowed only few clients to access mail via web (DWA). The restriction is working fine on lan/internet.

But using the following web site, any user (restricted or not) can access DWA and can login to see his email.

http://www.mail2web.com/

Here I enter user id passwd who is not allowed, but he can access email using DWA using this web site. What should I check or do ?

Subject: [SOLVED] mail2web.com ignoring DWA Access Restriction

Temporarily workaround:

I blocked mail2web.com subnet ip range (servers which access mails on other domain) on my main router so they cannot touch my mail server anymore.

There ip range is from

168.144.108.0/24