Hi Hollie! This is Raech. I'm an Outlook.com user like you and I'm sorry to hear about the issue you are having.
There are several possible factors as to why you're not receiving your emails. Below is a list that you can check to ensure that your settings are optimized to receive all your emails accordingly.
1. Check your Junk folder for the missing emails.
2. Make sure your mailbox isn't full or close to its limit.
3. Check your Inbox filter and Sort settings.
4. If Focused Inbox is enabled, check your Other tab for the missing emails.
5. Check your Blocked senders and Safe senders list. (You can add domains from known senders in your Safe list)
6. Check your email rules.
7. Check to see if email Forwarding is enabled.
8. Check if your account is blocked.
9. Remove some connected accounts in excess of 20.
10.Contact the sender and inform them about the issue so they can also check on their end.
For specific instructions on the items listed above, kindly check the link below.
https://support.microsoft.com/office/fix-outloo...
For the sending issue, could you please tell me if you are getting any specific bounce back error?
Disclaimer: This is a public user-to-user community forum. None of us here work for Microsoft and it is beyond our capability to assist directly with account or login-related issues.
Sincerely,
Raech C.