Some of my icloud email is blocked

See the article for IMAP account https://support.apple.com/en-in/guide/mail/cpmlprefjunk/mac

You can select the mail address or trusted number and click on subtract sign applied for Mac OS catalina 10.15.6

https://support.apple.com/guide/icloud/set-up-filtering-rules-mm6b1a3f8a/icloud

1. In the Mail app on your Mac, choose Mail > Preferences, then click Rules.
2. To review an example of a rule, select a provided rule, then click Edit. To close the rule, click Cancel.

Also advanced rules mhttps://support.apple.com/guide/icloud/set-up-filtering-rules-mm6b1a3f8a/icloud

That has to be cancelled for specified mail address .

If you are viewing mails from iCloud .com check if any rules are created for specified mail address https://support.apple.com/guide/icloud/set-up-filtering-rules-mm6b1a3f8a/icloud

Try - Get help using iCloud Mail - Apple Support.

It may have to do with Apple's silent filtering - Why is Apple silently discarding mail sen… - Apple Community.

So email is not coming to you or it's going to the sender?

You can try outreaching to Apple Support and have them escalate the issue to a senior technician to possibly notate the account.