You can delete messages for everyone or just for yourself.
To delete messages for everyone
Long press the message which you want to delete, you will get a delete option
Press the Delete button, you will get two options: Delete for everyone or delete for yourself:
Deleting messages for everyone allows you to delete specific messages you have sent to either a group or an individual chat. This is particularly useful if you sent a message to the wrong chat or if the message you sent contains a mistake.
Messages you successfully delete for everyone will be replaced with "You deleted this message" in your chat, "This message was deleted" in your recipients' chats. Similarly, if you see "This message was deleted" in a chat, it means that the sender deleted their message for everyone.
1. If you or your recipient are not using the latest version of Mixin Messenger for Android, or iPhone, this feature will not be supported. In order to ensure delete messages for everyone, both you and your recipients must be using the latest version of Mixin Messenger for Android or iPhone, please check the update frequently.
2. Recipients may see your message before it's deleted or if deletion was not successful.
3. You will not be notified if deleting for everyone was not successful.
4. You only have about an hour after you've sent a message to Delete for Everyone.
To delete messages for Me
Deleting messages for yourself allows you to delete your copy of messages you've sent or received from your phone. This has no effect on your recipients' chats. Your recipients will still see the messages in their chat screen.