A couple searches I’d like to be able to perform easily, but can’t:
# I want to be able to search and find conversations, not just individual messages. E.g., let’s say I remember that I received a message from friend A and forwarded it to friend B and later friend C. Apparently if I search for “A and B and C” then Gmail won’t find anything, since each individual message within the conversation is just between me and A, me and B, me and C.
# …Search for messages sent more than X number of hours ago. There are browser plugins that can fake this, but in terms of what Gmail supports, when searching by date I need to put in a specific date, not something like “today” or “yesterday” or “24 hours ago”. For example, I’m using the “Multiple Inboxes” Labs plugin, and it’d be cool if I could create a filter which highlights messages older than 24 hours so I’ll know to deal with those first.