Sending emails to people who will read/answer them on shabbat

Question

Is it permissible to send an e-mail on Friday afternoon, knowing it will be answered or at least read on shabbat by a Jew? I am inclined to think that, since the alternative to someone reading/answering my e-mail on shabbat is other internet browsing at least and deorita melachot at worst, it would be ok (assuming they don't go and do melachot deorita as a consequence of the senders e-mail).

Sources would be well appreciated.

I know there is a similar question, but it is about sending the e-mail while it's already shabbat for the recipient.

Answer 1

Per the article here by Rabbi meisels it is allowed. He explains that לפני עוורand מסייע do not apply here, as the reader might not even know that it was sent to him on shabbat. And even if he knew, he doesn't have to open it on Shabbat and read it.

Answer 2

See also this article Emailing to a Non-Observant Jew Close to Shabbat by Rabbi Ari Wasserman which concludes:

Having established that there is a problem, the question remains how long before Shabbat do you need to send the email to be sure you are not in violation of the Torah prohibition of lifnei iver.

On the one hand, if the recipient checks his email all of the time — as most people do — you can send the email to him relatively close to Shabbat, since he’ll very likely open it promptly upon receipt (before Shabbat starts). But, if he typically does not check regularly, you would need to refrain from emailing to him for a longer period of time before Shabbat starts.

I posed your question to Rav Yitzchak Breitowitz shlit”a, who responded as follows: “I believe that sending an email before Shabbos is permissible provided there is enough time before Shabbos for the recipient to open the message. As a somewhat arbitrary rule of thumb, I would suggest that Friday emails be sent to non-religious Jews no later that one hour before sunset (shekiah) wherever they are located.” [Emphasis added].