You could have downloaded thunderMail 1.0 from our software library for free. The default filename for the program's installer is ThunderMail.exe. This free software is a product of Kenneth McInnes and Kyle Donnelly. The most popular version among the program users is 1.0. The program relates to Communication Tools.
From the developer:
Thundermail is an easy to use email program designed for kids. This program makes email simple and safe for your kids where they will have a list of friends who they can send and receive mail from, stopping spam and unwanted emails coming through. Thundermail is a stepping stone for kids before using full email clients such as Microsoft Outlook and others.
You may want to check out more software, such as Thunder Mailer, which might be similar to thunderMail.