I recently became acquainted with SimpleJavaMail. I've been testing it for a few days, and so far, I like it very much. Thank you very much for making it, and sharing it with us!

On your website, you asked for suggestions for how it could be improved. I have a few "wishlist" items for it. I'll put them in separate tickets so you can evaluate and track them individually.

Please consider adding a method to set Return Receipt Requested information:

email.setReturnReceiptRequested(MsgFromAddress) // or other address

if (bReturnReceiptRequested) {
   msg.setHeader("Disposition-Notification-To", getMsgFrom());
}

Yes, we could set it with a custom header, but it would be nice if we didn't have to program it ourselves -- especially so people don't need to learn the intricacies of mail headers.