It is now required that anyone sending bulk messages to people in the US must register their campaigns with Twilio and the carriers. Once this is set up, the carriers will start to allow messages from your brand to arrive every time.
To get started, login to your Twilio account click on Develop, Messaging, Regulatory Compliance and then Onboarding.
Start by filling out the required fields to identify your brand and your messaging. You will need key business info such as the FEIN in order to complete this.
If you have not already done so, make sure you select a phone number in the Peoplevine interface. Once selected, you can then assign that phone number to this campaign. This will ensure messages from this phone number, sent via Peoplevine, are not blocked.
We also recommend you review Twilio's Acceptable Use Policy and other guides to ensure messages are delivered to the inbox.