You can now check how does your email template looks like when you send it to different providers such as gmail, yahoo, and hotmail.
There are no best software that examine how does an email template looks like when you send it to your subscriber.
Test Mail isn’t a software but a simple but powerful webpage. This is the best tool to test email because you can see it online and it’s faster compared to other test mails online.
After a few seconds you should receive an email. If not, check the spam folder.