If nothing other than simple efficiency, most of the major e-mail services (Yahoo, MSN, Gmail, Hotmail, AOL, etc.) do not support e-mail return receipts. Even when a sender uses a tool that does assert return receipts, such as Outlook or Thunderbird, many of these services simply ignore return receipt requests and do not create them and send them to senders.
There is an opportunity to change all that. The tool ReadNotify restores the ability for a sender to know whether a recipient has read an e-mail message. The beauty of this is, it works even for the email services that do not support traditional return receipts.
ReadNotify has a 30-day free trial. After that, choose from either the Basic (US$24/yr) or the Premium (US$36/yr) subscription plan.
If you really need to know whether certain e-mails are actually read by their recipients, ReadNotify may be for you.
Certified Return Receipt
A really nice feature available in ReadNotify is digitally signed return receipts. This option will digitally sign your email and insert a timestamp certificate. This certificate irrevocably links the body and headers of an email to the date and time they were dispatched – and may be offered as court admissible evidence if required.
ReadNotify supports several other features, including Ensured (stored on ReadNotify servers until the recipient reads it), Retractable (body of message can be retracted), Self Destruct (message can be destroyed prior to user reading it), Block Print (prevents user from printing – well it slows them down anyway), Invisible (recipient will not be aware of your tracking), and more.
Caution: ReadNotify was apparently used to track e-mails in the HP e-mail scandal. Seek legal advice if you are unsure whether your use of ReadNotify is legal.