When I send someone an e-mail how long does it take them to receive it?

When you send mail it is almost instantaneous. After that how long it takes to get there depends on how the mail is delivered by the recipient’s ISP. Many large online services like America Online and Prodigy queue their mail. What this means is that all mail messages that are delivered to their networks are held in a temporary storage bin until the server has time to deliver it to the person. If the mail server is very busy it can take days to deliver. On the other hand, sending mail to someone on another local ISP will happen almost immediately.