Definitely, I also have many things that triggers me and I don’t have always the smartest reaction to be honest.

What it works for me in these situations is first, try to keep a little of distance so I have the change to cooler myself ( this is something you can get by many means, and each person gets it by doing different actions, it has to be with change the state of mind basically and distract yourself from the situation, walking, meditating, writing on a journal, etc).
After that I try to second look what triggered me in a more objective way, mainly to test two things: on one side, whether I was able to see the situation in an objective way or I was more lead by my emotions. On the second side, I’m very curious to know why a particular situation triggers me. What it is telling me about. To see if there’s any pattern and I can put some kind of sense and order.

After all that, I take my conclusions and take choices.

Wow! It’s not easy. I’m still in a 20% of achievement in this process. Most of the time, I react, I attack to protect myself or I let myself down and complain about my unfair luck.

There are so many reasons by which a person may do something that I don’t like. Mainly, because they aren’t us.

Look, in your example, about replying to a message. I would also feel triggered. But, my response it would be very different. I would think this person didn’t like me or finds me boring or something negative about me. What I thought might be truth but it could also only be that this person didn’t receive my message. Or maybe, doesn’t have anything to reply.
Each case it’s different and by distancing yourself enough to be able to see it more objectively, helps to find a peace of mind.
Many times, we don’t find another option that this person is not a person you might be interested in going on touch. Simple as that.

Sorry for the long post. lol! But, as it’s something I’m trying to work on it currently, it’s a topic that touches me.

A side note: I wouldn’t ever ever ever dare to not reply your messages. Just in case. lol!