When running the User Defined Profile Export, the only field that interacts with the Mailing tab options is the "Address" field:

User-added image

This Address choice includes most, if not all, the values you need to produce a mailing.  To see what fields are exported, choose The alphasort name, idcode and address field as shown and select an affiliation code with a few members.  Run the export and open in excel.  You will find that in most cases these are the only 3 fields you need to include in your export when doing a mailing.

When you choose other salutation or address fields you are overriding the built in logic of the Mailing tab and forcing the selections to come directly from the Profile 1 or Profile 2 tabs.