A. A. First read the manual - SQL provides a very good, searchable, books-online.
After that go to http://support.microsoft.com and check out the following SQL Mail knowledgebase articles :-
Q118501 for MS-Mail post-offices
Q153159 for Exchange post-offices
Any other problems then do a search for "SQLMAIL" in the knowledgebase and you'll find other more specific articles.