If you use Gmail, you will know all about organising conversations using labels. To find all conversations with a specific label, select ‘Show search options’ and choose the label you want from the dropdown list called ‘Search’. Easy.
But what if you want to find conversations with multiple labels? For example you are interested only in messages labelled ‘Sales region 2’ and ‘Quarter 3 2010’.
Instead of going into ‘Show search options’ simply type your search into the search box at the top of the Gmail screen thus:
and click Search Mail. This will return a list of conversations containing both labels. Note that the label names are case insensitive, but you must replace spaces with a hyphen.
What if you are interested in messages with either label? Then you would use:
label:sales-region-2 OR label:quarter-3-2010
The OR operator must be uppercase. Alternatively you can use the pipe operator ‘|’ (shift+backslash on your keyboard) like this:
label:sales-region-2 | label:quarter-3-2010
You are probably three steps ahead of me here, and wondering about other compound searches. In fact you can choose from a long list of “query words” to build up a very specific search. In Gmail see Help articles › Using advanced search for the (almost) endless possibilities!