I am from The Gender Lab, Mumbai. We need a platform through which we can send text messages to our all the stakeholders together. It would be great if you can share some ideas. Apart from this also some options to send emails.
For bulk SMS, Exotel seems to be a very good platform. You can see more on https://exotel.com/bulk-sms-marketing/
They give the option of setting up Bulk SMS Campaigns, and importing an existing contact base is all so intuitive enough. You should check it out.
For really simple Free email newsletters for up-to 5000 Subscribers - Try https://tinyletter.com/site/