ReturnReceipt
www.returnreceipt.com
ReturnReceipt tells you when email you've sent gets read. No. ReturnReceipt already works with your existing email client.
Much
more! We also have Self-Destructing Emails, Ensured-Receipt emails,
proof-of-posting certificates, proof-of-delivery certificates, message
retraction, and many other useful features. Simply add: .returnreceipt.com to the end of your recipients email address. (eg; drakecn@yahoo.com.returnreceipt.com)
This directs your email through the ReturnReceipt servers, where it is
assinged a tracking code. When your email is opened by your recipients,
this tracking code transmits a message to our server which confirms the
date and time your email was read.