If you’ve decided that you don’t want any mail from a particular email ID, you can set up filters to automatically delete these mails before they reach the inbox. For this you have to…
1. Gmail Open > Sign > then click the arrow down icon next to the blue search button in the top-right corner of the search bar.
2. Now in the From section, enter the email ID that you want to block. You can enter a specific email ID (firstname.lastname@example.org) or the entire domain itself (@abc.com) > then click on Create Filter > Check Delete It > Then Click on Create Filter. Doing so will automatically move the incoming mails from that particular email ID to the Trash folder. You will not receive any notification for these emails and they will be automatically deleted after 30 days.
3. If you are on any mail and want to block that id then you click on down arrow button appearing next to reply. After this, go to Filter Message Like This. Now follow the previous instruction.
Gmail does not allow the user to block any mail id to prevent them from sending mail. If you don’t want email from a particular mail id then follow the above instructions.