Well, you could just discipline yourself to save outgoing emails in your `drafts` folder for a bit and read them again before you actually send them. That's what I do for most emails and it works pretty well for me. That is a good advise. I'll give it a try. Anyway, one of the reasons which brought me into this post is the fact that I use Gmail, with Gmail, there is a short-cut for 'send' by hitting <tab> and then <enter>, It happened more than once that I typed this sequence without any intention to send the message and ptooof! the message is gone. I simply wanted a new paragraph but the message has already gone. I am afraid this one has not been proofed by your suggestion.

I couldn't understand what do you mean by delaying messages. I never meant to create a delay but an ability that my server will withdraw the message from the recipient's server if I asked for it and the recipient has not yet been aware of my message, that is, didn't logged in to the server since I sent or something alike .