Adobe DC secure for critical personal information transmission or retrieval?

An employer is demanding I send a tax form to him via email or PDF Creator - a tax form containing my social security number.

IRS recommends USPS for critical information transmission. The employer states he is not in one place long enough to receive mail and insists that I transmit my document to him via email or PDF creator.

I have Document Cloud. Can anyone provide guidance on a solution path that will protect my critically sensitive information?