You can feel it without sending it.
You read the message once. Then again. By the third reading, you are answering not just the words on the screen, but every conversation that seems to be hiding behind them. The first draft is growing. So is the temptation to send it.
For a nonurgent message, a draft can be somewhere to sort that out. It is allowed to contain the sentence you never send.
What do you need this reply to do?
When you come back, look for the actual request. Are you asking for clarification, setting a limit, correcting a misunderstanding, or trying to repair something? A message with one clear purpose is different from a message trying to settle the entire relationship.
Keep the necessary information. Remove the guesses about someone else’s motives. Trade the final insult for a direct question. You do not need to make the reply weak to make it deliberate.
Give the pause an edge.
Waiting is not the same as ignoring someone. A simple acknowledgment can keep the conversation open: “I have seen this. I want to answer it thoughtfully. I will reply tomorrow morning.”
Use the pause where you actually have time. Urgent safety needs, time-sensitive work, and responsibilities to others still matter.
A smaller next step.
Write the version that gets the feeling out. Do not send it. Then write the version that helps the conversation move forward. Those are allowed to be two different documents.
I have seen this. I will give you a thoughtful answer tomorrow morning.