how does e-mail work

[Kratt]

when my server crashes, or is hung, e-mails are lost. From what I thought I knew, the server sending the e-mail only considers the e-mail sent successfully if it gets an acknowledgement from the receiving server. So if my server is hung, how is it able to make the sender think that it was successful, and yet lose everything when it is rebooted ?

[matty005]

Loads of info on email: http://en.wikipedia.org/wiki/Email

[Canuckkev]

Sounds like either the sending server isn't queueing the message properly, or your email server is doing something to mess it up. Probably exactly as you say, your server makes the sender think the message was successful, but your server somehow loses the message...of course, read your email server docs.