Are unsent / edited messages delayed on iPhone?

Now that outgoing messages can be unsent and edited on the iPhone, iPad, and Mac, people are wondering how this affects message delivery times. For example, does iOS 16 and later wait to deliver a message until the time allowed for Undo Send passes?

No, messages are sent immediately as before. Instead of delaying a message, the Messages app sends it right away. Users then have two minutes to Undo Send and 15 minutes to make edits to a sent message.

Messages notifies the recipient when a message was unsent and removes it from any conversation thread. Edited messages are marked edited and changes can be viewed by the recipient.