I can't seem to find documentation on this. If I pass forceDelivery when constructing a message, how will the API behave differently compared to not passing it?
The only documentation I see is
<param name="forceDelivery"> The force_delivery </param>
which is rather useless.
No kidding ... there is seriously no documentation on this. After a good bit of digging though, I found that Raj Rajamani, when he was Director of Product Management at Marketo, committed TwilioUtility.java to his Marketo repository, in which there are these lines of code:
/* perform additional check on phone number to see if it can receive SMS */
params.put("ForceDelivery", "false");
This seems to be consistent with the few comments I've seen around the internet in which people indicate that setting ForceDelivery to true will tell Twilio to skip validation of the receiving phone number.
Hope this helps.