Gmail search, in plain words. Describe what you're looking for: the tool writes the exact Gmail search query and shows what each piece of syntax does.
from:amazon OR subject:invoice has:attachment older_than:6mfrom:amazon OR subject:invoicesender or subjectolder_than:6magehas:attachmentattached fileSee the full library: every operator with examples, what it does well and its limits.
from: / to: / cc:sender, recipient, copysubject:word in the subjecthas:attachmentwith an attachmentfilename:attachment name or file typeolder_than: / newer_than:age, e.g. 6m, 1y, 10dbefore: / after:exact date, YYYY/MM/DDis:unread / is:starredmessage statuslabel:Gmail labellarger: / smaller:message size, e.g. 10M"exact phrase"word-for-word searchOReither criterion-wordexcludes that term