Dear RG_50
Welcome to Microsoft Community.
According to your description, you can't receive emails from a specific sender on business.com using your old Hotmail mailbox, but you can receive emails from the sender using the new Outlook, right?
For this question, I see that you indicated that the sender's email prompts successful delivery, at the same time, combined with your use of the same Microsoft domain name mailboxes, one can receive, one can not receive, I initially judged that there may be a problem with your Hotmail mailbox settings or account, I need to explain to you.
In this regard, I need to explain to you, due to the community personnel received Microsoft privacy restrictions, is not any authority and tools can view and modify your account information, we only through your text description, to determine your problem and specific solutions.
For your problem, I suggest you to use your Hotmail account to log in through the web version of Outlook and check the settings according to the following process:
Spam:
You in Outlook, click on the upper right corner gear settings - mail - spam, check whether the blacklist by you can not receive mail business.com specific sender's address, if there is please remove it, at the same time, I recommend that you add the other party's address to the safe sender, after completion, to confirm whether it can be normal to receive.
Check the rules:
You are in Outlook, click the gear settings in the upper right corner - Mail - Rules, and then check if there is any specific rule that affects the specific sender's address of business.com, or you can stop all the rules you have set, and then test if the emails can be received or not.
If you check the above settings are normal, then your problem may be related to your Hotmail account, for this, I suggest you contact Microsoft human support through the following ways and try to let the other party to intervene and check the status of the account for you:
- Click the link.–Contact - Microsoft Support
- In the box under “We're here to help,” enter Outlook, click Get Directions, and then click Contact Customer Service. (You must be logged into your Microsoft account. If not, follow step )
- In this section, you need to sign in to your personal Microsoft account.
Note: You can only sign in with your personal MSA, when you sign in with your company account, it will not display correctly. If you are unable to connect to this account, you can use another account or create a new account to manage it.
- Under “Products and Services”, select “Other Products”, select “Outlook”, and then click Confirm.
- You can select “Chat with a Support Specialist in a Web Browser” and go to the chat window.
Note: Please contact us during local business hours on weekdays, CHAT is not available 24 hours a day.
Feel free to text back if you need further help.
Best wishes
Chris.S-MSFT | Microsoft Community Support Specialist