Messages sent by Internet clients are stored in Multipurpose Internet Mail Extensions
(MIME) format, and no message conversion takes place when the
messages are read by clients. Messages sent by MAPI clients are
converted from Microsoft Rich Text Format (RTF) to MIME by Simple
Mail Transfer Protocol (SMTP). Use the procedures in this section
to specify how SMTP converts outbound messages sent by a MAPI
client to an Internet client. You can associate MIME content types
with an extension to ensure that messages convert correctly. You
can also specify how all messages sent to a specific domain are
converted.