Assalaamu alaykum Shaykh. I had started a broadcast list on WhatsApp to send reminders to some relatives and friends for the Dhuha prayer, the adhkaar (expressions of remembrance of Allaah) to say before sleeping and the white days for fasting, amongst others. I do not send reminders everyday though, just once in a while. When I started it, my intention was to enjoin good and help one another in Birr and Taqwa (virtue, righteousness and piety). Some of the people whom I sent this to used to ask me to remind them of these forms of worship and others appreciate it now. Some of them wanted to know what the Dhuha prayer was as they did not know about it. In India, there is always confusion about the lunar calendar, so I check with the local Islamic centre before mentioning when the white days are. Recently, a sister read an article by Jamaal Al-Harithee in which he says that this practice is Bid'ah (religious innovation) as it was not an action from the Salaf (pious predecessors). She asked her Quran teacher from Egypt, who also said the same. Please let me know whether I should stop sending reminders. May Allaah reward you.

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger. 

There is no harm in sending beneficial messages by WhatsApp or Viber or other modern means of correspondence, and there is no Bid'ah (religious innovation) in this as long as the messages themselves are free from Bid'ah.

We do not see a reason to say that sending beneficial messages by those means is Bid'ah. What Bid'ah could there be in reminding the people to fast the white days or to pray the Dhuha prayer or to teach people about prayer, fasting and other Fiqh rulings?!

Indeed, Allaah urged in His Book and in the Sunnah of His Prophet to invite people to guidance, to spread good, to remind and urge them to do so, and to cooperate in righteousness and piety.

Therefore, dear Sister, you should continue in doing the goodness that you are upon, and what is important is not to spread what is not permissible in Islam.

Allaah knows best.