Indeed is mostly aggregate job listings that are old by the time indeed web crawler brings it to the board. Even if the job listing is valid, it's unlikely any one in busy a HR will even care to see an email from indeed with a resume attached. Has any one really looked at some of the resumes? Many are just plain bad.
Of course HR can post openings directly to job board, but why put out the effort? Employers tend to fill openings from within. It's more comfortable even if it breeds cronyism. I also doubt any employer really trolls through indeed resumes in search of a candidate. It's an employers market, resumes are pouring in so much a cv scanner does all the work of sifting through applicants. The scanner is set to disqualify almost everything to eliminate traffic and discrimination liability.
I'm afraid the only way to land a job is have a connection on the inside or walk in and get lucky. Passive job search is unlikely to develop any thing but black hole efforts.