Introduction

There are two types of electronic mail that you might want to deal with: internal LAN mail and messages destined for users on the Internet. There are several different email standards that define how messages are transferred between the sender and receiver. The mail standards used for LAN-based messaging and for Internet or WAN-based messaging tend to fall into separate camps; sure, you can use a standard, such as X.500 for LAN-based networks, but it is rare and only useful if your local network has many different servers and hundreds of users. To tackle the problems of email, I have split the subject into two separate sections for the two main standards: in this chapter I cover the MAPI standard used to send mail over local area networks, and in Chapter 6 I cover the SMTP/POP3 standard used for Internet, mainframe, or other TCP/IP-based networks.