Rated 5 out of 5 stars

Nice. It works. Thanks.

It would be nice if it would allow to add (and check) also the "@" part.

My use case: I'd like to treat "@gmail.com" as one domain, however "@lists.gmail.com" as other - warning required.

(Please note it's not literally for gmail.com, but you get the point.)

This review is for a previous version of the add-on (2.1). 

Rated 5 out of 5 stars

Nice idea. Very simple setup just one box to type it in.
I tried to use this add-on and got no warning dialog at all. I tried filling out with full emails and the @domain yet could not get this add-on to work.

Then the by Graeme Developer "Graeme" gave me a heads up. What I needed to do was put the domain only with no "@"
- gmail.com for example.

Thanks for putting your add-on "out there".

This review is for a previous version of the add-on (1.1.1). 

What you need to put in the setup is the domain - gmail.com for example - no @ no email address.
Try out CheckDomain - it has a similar idea about allows for more accounts.
Blessings
Graeme