addressheader.email
If the address header consists of a single simple address, returns the email
address portion of the address. For example, if the address is "John Smith
<first.last@example.com>
, addressheader.email
will evaluate as
first.last@example.com
.
If the address header is not a single simple address, raises an error.
If the address header is a single simple address, but has no email address,
returns nil
.