A particular domain is blocked in your BT Mail, which is the reason the important emails from a client are not showing in your inbox. You have checked everywhere but have not been able to find that email. So, what you need to do now is unblock the domain.
It is easy to unblock a domain in BT Mail. Here are the instructions that you need to follow:
Open your web browser, and go to the official website of BTinternet.
Now, click the My BT option in the top menu bar, then click the Login option.
Log in to your BTInternet account.
Open the Settings tab.
Open the Mail dropdown in the left panel, then click Blocked senders.
Find and click on the Delete button to unblock the domain.
Once you are done with the unblocking process, the missing email is back where it belongs. Whenever a legitimate message can’t reach you, just remember the process above.
All your work-related emails will be delivered to you timely manner and not sit in the spam folder. You can have a smooth emailing experience.
Source:- Unblock a Domain in BT Mail