Searching for emails containing specified text string in body of email messages in MacOS mail Does anyone know how to search within Apple Mail (on MacOS, or iOS) for emails containing a specific text string (e.g. MacBook).
It used to do this by default, but it seems that more recently it is only possible to search headers, sender, etc. ;but not the body of the text. Unless I'm missing something?
This is extremely inconvenient as I used to use the emails as a sort of filing system and now this doesn't seem to be possible. the result is that now I can't find important emails. For example, and most frustratingly, I'd search for invoices from apple when I purchased hardware (like a MacBook).  However the name of the item purchased in not in the header, but in the body text. Now I can't find invoices without a huge amount of work.
I can't be the only one who used emails like this, yet I can find no mention of this issue anywhere. Does anyone know of a workaround? Or is there another mail client, app or software that can search my email body text and identify the requisite emails?
As an aside; does anyone know when this change occurred. I suspect it was with the introduction of Catalina, but I can find no reference to this change being made.
Any help much appreciated.
Searching is performed in whole messages but one can do it explicitly as well.
There is drop-down list of options from which one can select 'Entire Message':

There can be several reasons why mail is not found. One of them could be indexing failure on Mac side and another is IMAP settings of mail provider (there can be limit set for number of mails in local machine)