Since none of the two parties can message each other when one of them has been blocked, so there is no chance of missing messages or retrieving them after being unblocked.
Will my messages reappear after I unblock someone? If you block someone on Messenger, you can still see all of the messages you've sent and received. This means that you can still see everything after unblocking the other user.
Blocked messages will not come through when unblocked.
While someone is blocked, any sent text messages will be blocked by Messages. You won't be able to retrieve them. If you decide to unblock the person, you will receive the texts normally.
If you block someone and then unblock them, you need to wait 48 hours until you can friend them again.
If the person you blocked sends you any messages in Direct, you won't receive those messages, and they won't be delivered later if you unblock them. After you block someone, they won't be able to join a room you create if they're logged in to their Instagram account.
When you unblock a profile, that profile will be able to see your posts on Facebook that you share with the public. The profile won't automatically become your friend on Facebook. If you want to become friends with a profile you've unblocked, you'll need to send a friend request to that profile.
When someone that you've blocked texts you, their texts go nowhere. They won't receive any notification that they're blocked, and their messages will still look like they've been sent. But you won't receive any of them, and you can't respond.
When you block messages and calls from someone's profile, they can't: Chat with you on your Messenger app or Facebook Chat. You won't receive messages or calls from the profile you've blocked.
Keep in mind, if they blocked your number directly through their carrier, unblocking your number using the steps in that support article would not be sufficient in allowing you to send messages to them. They would need to contact their carrier to remove the block.
If someone blocks you and then changes their profile picture, you won't see the new profile picture - you'll always see whatever the image was when you got blocked. This means that there isn't a definite way to tell if they're updating their profile picture.
How can I see my blocked call history Android? To view your blocked call history on Android, open the Phone app and tap the three dots in the top right corner. Tap "Settings" and then "Blocked numbers." If you have blocked calls, you will see a list of blocked numbers here.
Blocking Someone on Facebook Messenger
However, you also have the option of blocking the person's messages, just on Facebook Messenger. You'll be able to see their messages in shared groups or rooms, and you can still see their posts and comments, but you will not receive messages or calls from their account.
If an Android user has blocked you, Lavelle says, “your text messages will go through as usual; they just won't be delivered to the Android user.” It's the same as an iPhone, but without the “delivered” notification (or lack thereof) to clue you in.
Settings & Privacy, then tap Settings. Scroll down to Audience and Visibility and tap Blocking. Tap Unblock next to the profile you want to unblock. Tap Unblock to confirm that you'd like to unblock the profile.
If you send a message to someone and they don't read it within 14 days, the message will automatically disappear from the chat. From Chats, tap on the secret conversation. At the top of your chat, tap the person's name or the group chat name. Tap Disappearing Messages.