A poster on macOSXHints notes that 
Leopard Mail now supports Spotlight sophistication in its searches.
This means that you can use a limited set of operators to construct more complex and better-targeted searches than you ever could before. Spotlight in Leopard can filter results by metadata categories like “author:” or “date:”. Leopard Mail does the same thing.
For example, this search lets me quickly find all the emails sent from a Christ Church South Yarra email address that contain the word “beer”. Not as many as one might think! Still, the search enables me to find quickly that the answer is Boags.
Another search from work yesterday quickly finds all the emails from the Director of Communications at College which contain the word “font”. Without too much browsing I discover that Optima is the approved font for all external communications and can get on with actually writing one.
A third example. This search lists all the emails that have arrived since 3 December that mention Tiger, including the one from a Hawk Wings reader who wonders why I don’t post about Tiger Mail anymore.
Not everything about Leopard Mail is focussed on greater productivity, but this smarter way of digging through your email and finding what you are looking for is a great leap forward.
After a few posts carping on about this or that failing in Mail.app, it’s good to stumble on something like this and remember what a truly great email client it is.
From my initial experiences and trials with this, it also will find messages with MailTags Keywords even if MailTags is not installed!
eg keyword:@followup from:bob
but it won’t find for project, duedate etc (or at least yet! — I will have to fix it)
Unforunately, it’s not working for me. All searches are looking in the “From” field. Mail.app 3.1 in Leopard. Now, I can run those searches as true spotlight searches and it works like a champ.
So is there any way to do Boolean searches in Leopard Mail? In Tiger mail I use search terms like “Wozniak | Jobs | Hertzfeld” all the time and this is sorely missing in Leopard Mail. I have quite some eBay auctions and it’s quite confusing when people write you alternately under their real name, eBay member name or with no signature at all (so you can just search for the E-Mail address). The | helps me tremendously on Tiger, I still have Tiger on my main machine for this sole function while checking into Leopard updates on my notebook. So far no luck, so does anybody know about boolean searches in Leopard?
One thing I’d like to find is a plugin (or search feature) that lets me find mail that I’ve sent, that’s never gotten a reply. I sometimes fire off a couple of questions that I plan to act on, later, once I receive a reply and have more information available to me. If I never get a response, though, the item falls off my radar, until something forces me to remember it (generally, when my boss wants a resolution). :-) Anyway, again, it would be useful to find sent messages for which there’s no “next-message”, were you to have all of your mail in a single, threaded view.
John, I don’t know of anything that does this or any way to tweak Mail to get this done. Sorry.
[...] search syntax. You can read about some of the details of searching in Mail at the excellent Hawkwings blog. Basically you create a query in the search box in Mail. Once you have your query getting the [...]