Comment by lproven
18 hours ago
I've been on email since 1985 and had the same personal address since 1991. I've used about 20 or 25 email clients across a dozen OSes (counting all Linux distros as one).
Gmail has the best search of any email system I've found.
I think your problems are nothing to do with Gmail or its search, but are to do with things like Unicode character encoding, character sets and codepoint matching.
Gmail search is objectively awful. I can feed it verbatim phrases from an email I've checked exists and it won't find it. I've used parametrised queries and it fails.
I'm happy it works for you, but it consistently doesn't for me.
The reason feels obvious: they're handling exabytes of email and building a full search index just for me is expensive. They cut serious corners.