suppose you send someone a lot of emails every day and they claim to be
never receiving 5% of them or so. now you don't know if they are really not
getting them or just getting them and losing track of them. how does one
set google mail up to get verfication of receipt of the emal?
Return Receipt is a function of the mail reader and is not supported via SMTP.
Everyone disables Return Receipts by default nowdays (Outlook,
Thunderbird). Most companies control the generation of Return Receipts
via a group policy and disable it.
The best you can do is run your own SMTP server
From Gmail Help search:
GMail, like most other webmail services, does not offer any received
receipt and read receipt features. Normally, standard email rules
imply that if a Delivery Failure Notification has not been received,
the message has been delivered to the intended recipient.
Some email
Well there are other ways to know if the email was opened.
Google shows for example
http://www.returnreceipt.com
http://www.msgtag.com/Mail_Receipt_.html
These use the feature called web bugs http://en.wikipedia.org/wiki/Web_bug
to let some server know when the mail was opened. Users with
