Reply without matching the heat.
You do not owe an immediate reply to every difficult message. First decide whether replying now is useful, then choose the one point you want to address.
Choose whether to respond now
A pause is an option. You can say you need time, move the conversation to another setting, or decide not to engage.
Separate the issue from the delivery
You can respond to a concern without accepting insults. Keep your reply focused on the concern you are willing to discuss.
Do not argue with every sentence
Pick one concrete point. A line-by-line defence can pull you away from the conversation you actually want to have.
Make your limit clear
Say what you are willing to discuss and what you will do if the conversation continues in a way you will not accept.
“You’re one to talk. You do exactly the same thing.”Another way to say it
“I’m willing to talk about what happened. I’m going to pause this conversation while there are insults. We can try again later.”
A reply can acknowledge an issue and still set a limit.
An example is not a script you have to follow. Adapt it to what is true for you. Clearer wording cannot guarantee a particular response.