Notifications are sent from notifications-noreply@limerick.brightspace.com and emails are sent from email@limerick.brightspace.com. These emails may go to your students' junk mail folder, so you should get them to add them to their safe email addresses in Outlook.
The email address that agent emails come from cannot be set to your personal address due to how spam filters operate, but you can add a personal touch by setting the Name for the address, and you can set the Reply-To address if you want to receive replies.
Remember that a student can switch off email notifications from Brightspace if they want to so Announcements are not 'forced' to email, so you may want to use email for important notifications to your class too.