Question:
May one send an email before Shabbos to a mechallel Shabbos Jew who might check and/or respond to it after Shabbos has begun? If not, what is the latest time on Friday afternoon that one may email him without transgressing?
Answer:
E- mailing him right before Shabbos is a problem because you are causing him to read it on Shabbos. Depending on the material being sent, you have to leave enough time for him to read it and make the normal reply, before Shabbos.
Best wishes