I manage a mensual meeting on a very specific subject (HIQ and autistic spectrum), in a western megapole of 10 million people. Approximatively 40 people have come to one of my 20 activities organized so far.
How can I inform them about dates and subjects of next activities, given that people on the autistic spectrum have problems dealing with communication?
I have so far collected e-mails and phone numbers, and use mainly mail (in BCC) because it is easier. Initially they all gave me permission for that; some of them changed their mind and I took them out of my mailing list.
I also text to one person who said they prefered texting over e-mail but this is difficult.
These is an agenda on a password-protected website, but no blog, Facebook page, Twitter account. One possible complication using these is that I am vision-impaired, hence am easily overloaded by notifications.