Yes, I am having trouble with the password protect email approach as well.  I use Windows 10.  I just got a new laptop with Windows 10.  In prior years this worked fine when I was using an earlier version of windows. 

Now when I use the email feature within proseries to email to clients, it goes through the process of sending the email, and at the end I get a message saying "error. email could not be sent."

In fact, the email to the client has been sent (clients have advised me of this) and I am getting my preparer's copy of the same email in my outlook in box. 

However, the actual password protected pdf that is supposed to be generated and saved to the "emailed" folder is not being generated.   

So, in other words things are kind of working.   It is a hassle.   I was on the phone with a proseries tech on this issue, after waiting an hour, and his fix was to preview the password protected pdf and then save it separately as a pdf, and then email it separately to the client.   A hassle and time consuming and of course, means they don't care about fixing their software.