[shmde]

I have been cold emailing resumes in PDF format all the time. Do recruiters not even open it ?

[cpa]

They do, opening untrusted pdf from unknown senders is part of their job. It’s also one of the many reasons why cybersecurity is so hard!

[dsr_]

If you're sending to recruiters, they do. That's an expected part of their job.

If you're sending to people who currently aren't hiring, or are never part of the hiring process, and didn't ask for your resume -- I hope they don't open it, but they probably will.