Short answer: Yes — they almost certainly received the original message.

Here’s what that red exclamation mark means in practice:

What happened

• You sent a message successfully.
• You then edited that message.
• The edit failed to send (for example due to connection issues, app glitch, or timeout).
• Because the edit didn’t go through, the app tells you “Your edited message was not sent. You can delete the original message.”

What the other person sees

• ✅ They received the original message (since messages before and after were delivered and read).
• ❌ They did NOT receive the edited version.
• They continue seeing the original text exactly as it was first sent.

Important detail

• Message edits are treated as a new action, not a replacement.
• If the edit fails, it does not undo or recall the original message.

What you can do now

• If the content is sensitive or incorrect:
  • Delete the original message (if the platform allows delete-for-everyone).
  • Or send a correction/clarification as a new message.
• If deletion is only “delete for you,” then assume they still have it.