[Email_MXLookup] accepts a domain name as a parameter and returns a map of information about the MX record associated with that domain name. The map includes the domain, host, username, password, timeout value, and SSL preference for the MX record (in addition, cache and route are used internally).

When an MX record is looked up for a given domain first the User Routes specified in the Utility > Email > SMTP Routes section of Lasso Site Administration are consulted. If no user route is found then the MX record is looked up using the DNS lookup tag. MX records are cached after they have been looked up once. The contents of this cache can be inspected in the same section.

In general this tag should be used with the domain portion of email messages. For example, this tag might be used to look up the domain example.com from the email address joe@example.com rather than the domain www.example.com.

An optional -Refresh parameters forces the tag to refresh the cache rather than fetching an MX record from it. An optional -Hostname parameter specifies an alternate DNS host to use for looking up MX records.