Message filtering systems exist to protect subscribers from unwanted messaging such as spam, fraud, or abuse. Here are some guidelines to avoid having your message appear Undelivered.
URL shortening: Do not send links that have been shortened using shared public URL shorteners, such as TinyUrl or free Bitly links. When sending SMS messages containing shortened URLs, use a dedicated, branded short domain that belongs to your practice.
Use the domains you control when sending URLs/links in your messages. Like the shortened URL guidance above, you should only use a URL owned by your practice when you send links.
Don’t use emojis or unnecessary special characters/capitalization; watch your grammar and spelling.
Here is an example of a message that was detected as undeliverable. Using all caps and multiple exclamation points caused this message to fail.
