I'd use a Saved Search.

File|New|Saved Search.

Select Tags as the search criterion. You can set rules for individual tags or use is not empty to see all tags. If you do filter for multiple tags, you'll probably need "match any…" and not "match all…".

For instance:

message 1: urgent, important message 2: urgent message 3: important

If you have set up two rules in your filter, one for "urgent" and another for "important" tags, "Match all" will show only message 1, whereas "match any" will show all three messages.

The gutty bit of using a Saved Search is the picking through the folders list to select the folders you want to include in search. In your case, select all will probably be appropriate.

Thank you so very much - excellent