Actually...let me quantify the responses above.
Older mail systems, such as cc:Mail and Microsoft Mail, DID offer this
option. However, the nature of these systems was internal and proprietary ‹
Internet mail was not a common thing back then.
If I remember correctly, early versions of Exchange also had this option;
but again, it would only work within the Exchange system in the
organization. I don¹t know if Microsoft eliminated this.
IBM Domino, in a break with cc:Mail, never offered this option. IBM claims
the feature was not a frequently requested issue, and did not feel its
implementation was necessary.
Now, Internet mail clients do not offer this, because it would be an
exercise in futility. Once mail has left your internal system and been
routed to the ISP, it¹s gone. As an example of how fast mail gets delivered
within my organization, I can compose and send a message, and literally
within 5 seconds it will reach my intended Internet recipient. My message
has to travel 3 server hops before being handed off to my organization¹s
ISP: my mail server, our mail hub server, and our SMTP server (and we route
250,000 to half a million messages per day).
It¹s kind of similar to return receipts: unless the receiving organization
explicitly allows return receipt acknowledgements from Internet recipients,
they usually are pointless. (And NOT allowing RR is a simple but effective
spam deterrent method: if a spammer gets an acknowledgement that the email
address is valid..)
