Why is the email address in my Brightspace settings different to the login username?
This answer might help if you have delved into your Brightspace settings.
Answer
Your S-number (e.g. S123456) is the username that you will use to login to things like Brightspace, MySuffolk, campus WiFi, and so on. However, it is tied to a 'friendly' alias for your email (such as j.bloggs5@uos.ac.uk).
You can give this friendly address out to others as your email, but your S-number will always be the one that you use to log into things.
There's no need to worry as these are the same account.