Carrier Filtering
From time to time you may very well have some filtering issues from the Carriers that are not reported to us. There is no standard practice for carrier filtering and depends on each carrier. For some, filtering can range from a simple static list of prohibited terms to advanced machine learning systems and algorithms that work in real time. Regardless of the system, carriers keep their filtering systems closely guarded secrets. In turn, Betwext cannot say definitively how these systems work or why a particular message was filtered.
One of the biggest red flags for the carriers is NOT adding opt-out language like "reply STOP to unsubscribe" on your campaigns. Carriers won't tell us when their bots pick up this content missing from your text, but they will randomly filter when/if it is not included.
Please note that adding "STOP to end" on each of your campaigns and in all of your auto-responders is one of your best ways to be sure you're staying in compliance and to avoid filtering.
Here are some articles to help and may explain more.
You'll also want to remember the carriers have added a MAX number of sends per day depending on how your account was registered with the carriers. It resets at midnight pacific time daily. If you do not know remember how your account was registered you can email us at support@betwext.com please provide the email address you log into your account with.
http://www.betwext.com/carrier-filtering-work/