Testing Your New Configuration:

Test whether or not the change made to macro M in the configuration files modifies the rewrite process by directly testing the rewrite rulesets. First, you need to find out what rules are used to rewrite the address.

Use your knowledge of the flow of rulesets from the previous figure of rulesets to determine which rulesets to test. You know that the ruleset canonify is applied to all addresses. It is followed by different rulesets, depending on whether the address is a delivery address, a sender address, or a recipient address. Furthermore, the rulesets used for sender and recipient addresses vary, depending on the mailer that is used to deliver the mail. All addresses are then processed by ruleset final.

There are two variables that determine the rulesets used to process an address: the type of address and the mailer through which it is processed. The three address types are delivery address, recipient address, and sender address. You know the address type because you select the address being tested. In the example, the concern is the sender address.

There are two types of sender addresses: the sender address in the message header and the sender address in the "envelope." The message header address is the one on the From line sent with the mail. You probably see it in the mail headers when you view the message with your mail reader. The "envelope" address is the address used during the SMTP protocol interactions. The one that we're interested in is the one that remote users see in the mail—the header address.