my halacha rebbi in highschool taught us that we can send a text message or e-mail if you are positive that the person will receive it on chol hamoed (like if you’re in ny, don’t send a message to israel if yom tov started already…) and as for typing, i asked if i could write my poems on chol hamoed cuz i do it for total pleasure and he told me i should rather type it… i guess ask your rav what’s right for you…