Hi hgsmall 
Welcome to the Canvas Community! Thanks for posting your question here. The information that @trinity_clevela has given you is correct. I would like to clarify one thing, however. You asked about sending e-mail to students via Canvas. Technically speaking, Canvas does not have e-mail. It's called "messaging" as described in the Guide linked by Trinity. All Canvas users have the ability to set up their own notification preferences in their Canvas profile and choose how and when they would like to be notified about course events. So, for example, if you sent a message to all of your students via the Canvas Inbox, some of your students may receive that message via e-mail, but some of your students may have chosen to receive that notification via text message on their phone. Others may choose to receive the message notification via their Twitter account. It's completely up to each user in Canvas how you want to be notified...and the frequency of those notifications. Here are some Guides that explain how this all works:
How do I add contact methods to receive Canvas notifications as an instructor?
How do I set my Canvas notification preferences as an instructor?
How do I add an additional email address as a contact method in Canvas as an instructor?
How do I add a text (SMS) contact method in Canvas as an instructor?
How do I add contact methods to receive Canvas notifications as a student?
How do I set my Canvas notification preferences as a student?
How do I add an additional email address as a contact method in Canvas as a student?
https://community.canvaslms.com/docs/DOC-10591-4212710337
I hope this information is helpful to you, Hannah.
