IMAP criteria with multiple ORs

问题

I am using gmail's IMAP API to search for mails.

I use the 'OR' criteria to search for different keywords. This works well if I go one level only, i.e. something like

'UID SEARCH OR (FROM "somebody@email.com") (TO "somebody@email.com")'

however, it does not work when I try a longer expression like

criteria OR criteria OR criteria or criteria

which translates to (as far as I understand the syntax)

'UID SEARCH OR ( OR (FROM "somebodyelse@email.com") (TO "somebodyelse@email.com")) ( OR (FROM "somebody@email.com") (TO "somebody@email.com"))'

to make it clear I basically want all messages that are either sent from or sent to ANY of a given list of emails

The error I get from the libray is

[ 'A34', 'BAD', 'Could', 'not', 'parse', 'command' ]

any suggestions?

回答1:

Do not use parenthesis.

IMAP uses polish notation which does not need them:

UID SEARCH OR OR FROM one@mail.com TO one@mail.com OR FROM two@mail.com TO two@mail.com

There are cases where parenthesis are needed (as IMAP AND operator can take more than 2 operands): https://www.limilabs.com/blog/imap-search-requires-parentheses

回答2:

So if you have N expressions that you want to "OR" together, you would prefix those N expressions by N-1 "OR"s.

In Perl, for example, that would be:

$search = join " ", ("OR") x (@exprs - 1), @exprs;

来源：https://stackoverflow.com/questions/12809709/imap-criteria-with-multiple-ors