Assume positive intentions from the other person. Imagine them as having written with a genuine smile on their faces. Don’t think of it as them versus you, but you and them together against the problem. That defaults ambiguity to the more pleasant side and allows you to reply in a kind manner in turn. In general you get out of a conversation what you put into it, so add kindness.
That doesn’t mean you have to take abuse. But even if someone is unambiguously disrespectful (e.g. name calling) you can generally be respectful when pointing that out or simply not respond. Instead of wasting brain cycles getting more angry as you write the perfect zinger, let it go and you’ll forget about it soon enough. Focus on feeling better, never on making the other person feel worse.
If you do have to reply, don’t do so immediately. Let it marinate and respond when your initial feeling has subsided. That allows you to get some emotional distance between yourself and your work, thus seeing (and fixing) the problem in the thing not yourself. Waiting has the secondary effect that another person may reply in the interim, shifting the burden away.
When you feel bad, stop to think. Observe your own reaction and calmly try to realise why you’re feeling that way and what’s your goal. The introspection alone can make you see that the situation is unimportant and thus taking it personally is disproportionate.
The first few times might be hard but eventually it becomes second nature as you adapt and find the approach that works best for you.