To delete individual items from OS X 10.11 El Capitan “Messages 9.0” app. *this is for deleting specific messages within a conversation thread. if the same Messages/iMessage account is active on multiple MacBooks, this will likely only delete the items on the specific macbook where you do this (ie., it doesn’t auto-delete the items from all connected devices).
- press and hold the command key
- click each of the individual messages to delete from a conversation.
- use the delete key.
It’s easy once you know the option is there, but it’s not obvious.
To delete individual items from a Messages conversation in iOS 9
- press and hold a finger on one of the items to be delete.
- look for the ” Copy | More… ” popup to appear.
- tap “More…”, now the selected message will get a checkmark and an option to delete.
- if there are multiple items in the conversation, each will now have a circle which can be checked (tapped) to select for deletion.
- tap the circles to select any additional messages to be deleted.
- tap “Delete All” at the top left of the screen.
*This doesn’t delete message items from other devices. Nor does it remove/retract sent items from recipients.