I need to send a message to all my contacts (309 phone numbers) via WhatsApp.
Is there a way to send a message for all my contacts, because the application just allows 25 contacts at once?
Use the broadcast function, see: http://www.whatsapp.com/faq/en/android/23130793
I don't think this is possible since it's a limitation from the App itself.. The best you can do is to put a status message so everyone can see, but you won't know for sure. Or you message them in groups of 25.
easiest is to select 1. chat icon at bottom screen 2. broadcast list OR new group at top screen 3. create yr contacts.