Etiquette of texting married men as a single woman?

I’ve heard from some people texting married men is a no-no, but I seem to find myself doing it

1) Drama that happens at work when one of us is away that the other person should be aware of
2) Arranging Mixed-sex off hours co-worker social gatherings when I don’t know my male coworkers’ wives
3) Sending male coworkers pictures from said gatherings
4) Dropping off baby gifts to a friend’s husband

Nothing ever inappropriate. But it still feels weirdly intimate to text someone else’s husband.
Etiquette of texting married men as a single woman?
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