this is a php server solution…
which means, if the server http://email.etvbanglanews.com/a/mailer.php which will be used to send the mail will go down, all apps, which use this extension will not work anymore…
yes, you will have to trust the developer of that solution, that your data will not be misused…
for other email solutions see the overview here App Inventor Tutorials and Examples: Send Mail | Pura Vida Apps
Taifun