# To

> [HTML Version](to_emailx2.htm)

The **To:** header field should not be confused with the _to _parameter. The former is used mainly by the email reader application to format the message, whereas the latter is a critical parameter given directly to the SMTP server prior to the message. The SMTP server only wants an unadorned address for routing purposes, whereas the email reader may appreciate a fancier one, possibly including a text name in addition to the actual address. The actual _to _parameter is typically not visible to the reader at all, whereas the **To:** header field is possibly the first thing he or she sees. An important ramification of this dichotomy between the _to _parameter and the **To:** header field is that if you want to send your message to multiple people, you must specify them all in the _to _parameter, but you do not have to (and may not want to) do so in the **To:** header field. (You might want to use the **cc:** or **bcc:** header fields instead, or not at all.). To see an example of this, just look at the headers generated by any mass-mailed message (or junk mail message.) Typically, the actual **To:** header line will have nothing to do with you, and your email address will not appear anywhere in the header at all.

Taking the example of traditional postal mail for comparison, the _to _parameter is analogous to the address on the outside of the envelope, whereas the **To:** header field is analogous to the heading or salutation at the top of the letter inside the envelope. Similarly, if you want to copy your letter to multiple people, you have the option of including a **cc:** header in your letter, but the only way the message will actually be delivered multiple recipients is if you use multiple envelopes (i.e. multiple _to _addresses.)