Message Recall in Microsoft Outlook - Make sense?

I received an email today which reminded me of a discussion I had with my potential customer some time back. (OK, I received 3 emails in actual fact since I am not on Exchange and this person is not from the same company)



Back then, I was trying to sell Sun Java System Messaging Server and the customer explicitly asked for a Message Recall feature which she found so dearly useful to her. I was amused. I probed further and realized she did not follow nor care about Internet Mail Standards and Protocols.

To know exactly how Message Recall works in Microsoft Exchange, read here.

Sometimes, it is very hard to convince customers that the feature(s) they are looking for are non-standard. And thus, even if deployed, they do not inter-operate well with other type of systems.

e.g. Sending an email from Microsoft Exchange to a recipient residing in Sun Messaging Server; then attempting to recall the sent mail. It's totally impossible to recall. The recipient will experience like what I did today - receive 3 emails instead!! (1 original non-intentional mail; 1 recall mail; 1 resent corrected mail)