So this is NOT an issue with Indigo, and NOT an issue with the Twilo plugin, but with Twilio. I've submitted a support ticket with them but while waiting for a reply, thought I'd ask the Brain Trust here to see if anyone might have some info.
I've been using Twilio to send SMS messages from Indigo for awhile now and up until recently, it worked just fine. Lately, SOME messages don't go thru. I was beating my head as to why and ended up checking the Messages Log on the Twilio website only to find a lot of messages were "Undelivered", with the error code in the attachment.
Funny thing is the only number I send FROM is my Twilio phone number, and the only number I send TO is my cell phone. Messages are only randomly delivered. At first I thought I was sending too many too fast, but that is not the case as sometimes hours after the last message, the next one hangs.... and sometimes hours after the last message, the next message goes thru.
Just asking if anyone has any ideas while I wait on Twilio Support.
THANKS