The optional relocated file provides the information that is used in "user has moved to new_location" bounce messages.

Table lookups are case insensitive.

The "Maps to..." field specifies contact information such as an email address, or perhaps a street address or telephone number. It's one of the following:

- `user@domain`: Matches `user@domain` . This form has precedence over all other forms.
- `user`: Matches `user@site` when site is `$myorigin`, when site is listed in `$mydestination`, or when site is listed in `$inet_interfaces` .
- `@domain`: Matches every address in domain. This form has the lowest precedence.

ADDRESS EXTENSION: When the search fails, and the address localpart contains the optional recipient delimiter (e.g., `user+foo@domain`), the search is repeated for the unextended address (e.g. `user@domain`).