Pdf asking for password

My husband just bought a galaxy note 7 and is having trouble opening email pdf files. After it downloads he tries to open pdf and it ask for a password. He can email me same email with pdf and I can download, view and print without any problems. My phone is a galaxy s5. Can anyone help.

from Android Forums at AndroidCentral.com - Ask a Question http://ift.tt/2bTldcS
via IFTTT