3.1.5 Message Processing Events and Sequencing Rules
The Autodiscover client expands the email address provided during initialization into a list of URIs, as specified in [RFC2396]. Because Autodiscover server URIs can be acquired in different ways, to create a fully populated list, the Autodiscover client SHOULD<2> do all of the following:
Query a well-known LDAP server for service connection point objects, as specified in section 3.1.5.1.
Perform text manipulations on the domain of the email address, as specified in section 3.1.5.2.
Search the DNS for Autodiscover SRV records, as specified in section 3.1.5.3.
Perform an HTTP GET request to determine whether redirects to other Autodiscover servers exist, as specified in section 3.1.5.4.
Note that a client can acquire the URI of an Autodiscover server without a fully populated list of Autodiscover server URIs.