Need more space in "blocked senders"

I deleted more than 100 senders from my "blocked senders" list a couple of days ago after getting en error message saying the list was full. I need more space or else another way to keep porno senders from getting mail to my junk mailbox. I have small grandchildren who are computer savvy, and even though they don't know my password, they are clever enough to figure it out. I DO NOT WANT porno stuff in ANY of my mail. I need either more space or a block that will block certain words and/or phrases if they occur in either sender or subject lines.

Update: I got a link and a forum moderator's "hook," but it was the same answer I got in my email. . . to go to a "link" (provided but not accessible or "connectable" by my home network) and then read an answer from ZigZagaq3143x. I found the forum, but the only answer in it was the same as in the email. . . to go to the "link," etc., etc., etc. Got a loop going here, and my question has NOT been answered. I suspect there is no answer.