If I saw double tick in Message module, does it mean that my contact has received & read my message?
If you see there are double tick, it is not necessary that all messages has been delivered or read. This function varies based on the channel you connect. If you connect to the below channel, please expect the following result
Available / Not Available
WhatsApp API - Gupshup
Available. Please enable it at your Gupshup portal (Gupshup dashboard → webbook → Message events settings)
WhatsApp API - Cloud API
Available by default
Available by default. Only have Seen function.