Ordinarily, one would do the formatting at the same time as inserting the mergefields, in an iterative process.

If you toggle Word's field code display 'on' (e.g. via Alt-F9), your mergefields should change appearance to something like:
{MERGEFIELD Name}{MERGEFIELD Address_1}{MERGEFIELD Address_2}{MERGEFIELD City}{MERGEFIELD State}{MERGEFIELD Post}
You can now add the required spacing, etc. between the }{ pairs. When you're done, toggle Word's field code display 'off' again (e.g. via Alt-F9).

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]