Hello danaaaaaaaaa,
It sounds like you have a question about the blocking contacts feature on your iPhone. If so, check out the information below regarding delivered messages from the article here: Block phone numbers, contacts, and emails on your iPhone or iPad
"When you block a phone number or contact, they can still leave a voicemail, but you won't get a notification. Messages that are sent or received won't be delivered. Also, the contact won't get a notification that the call or message was blocked. When you block an email address from Mail, it goes to the trash folder. Email blocking works across all your Apple devices."
However, there's no way to tell on your device if someone else has blocked you. If you'd like feel free to leave feedback for Apple directly here: Product Feedback - Apple
Take care.