@CarlThelen ...
If you send an e-mail to your students (using something like Outlook) prior to the course start date, you don't have to put all the addresses in the "To:" field of the e-mail. Rather, put your own e-mail address in that field. Then, put all your student e-mail addresses in the "bcc:" (blind carbon copy) field. This way, each of your students will not know who else was included in the e-mail. It only appears as if the e-mail was addressed to that one person when they receive it...not the entire class. When students reply, they are only replying to you...not to everyone else (eliminating the concern you have about "reply all" and sending personal information to the whole class). Here's a web page I found on Microsoft's Support site for how to send bcc e-mails.
Show, hide, and view the Bcc (blind carbon copy) field - Microsoft Support
The Canvas Inbox has a similar feature that you'll be able to use. When composing a message via the Canvas Inbox, there is a checkbox for "Send an individual message to each recipient". This is described in more detail under the section "Send Message" in this Guide: How do I send a message to all course users in the... - Instructure Community (canvaslms.com).
I hope this will help a bit. Let folks in the Community know if you have any other questions...thanks!
