Q. If I have to text or send emails during Chol Hamoed should I add a few words such as "kedushas Yom Tov", to make a change and establish the holiness of these days?
A. Remah (O.H. 545:) rules that one may be lenient on ordinary writing in need during Chol Hamoed (Mishna Berura ibid 5 and 35) maintains that one may be lenient in ordinary hand writing if he makes a shinui or a change, such as the top line being written in a slant. Yabia Omer (8: 48: 5)) opines that typing on a computer is also considered non-professional writing and not even actual writing, since the letters are not printed. He permits typing up Divrei Torah. or sending greetings for Yom Tov need. (See similar opinions in Igros Moshe E.H. 4: 73: 4 and Shemiras Shabbos K. 66: n. 211, Yalkut Yosef - Kivud Av Vaem p.251) and others).
Horav Shlomo Miller's Shlit'a opinion is that adding a few words into the text, would only make the situation worse as those words are unecessary and therefore not permitted.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit'a.