SMRT has an automated system to detect if a phone number is a landline or mobile. SMRT uses this information to automatically determine if notifications should be sent by text or email.
In the customer account, the icon with the customer's phone number next to it displays a smartphone icon if the number was detected as a mobile phone, and a telephone if the number was detected as a landline.
If notifications are enabled under the customer's profile and the phone number was detected as mobile, the icon is green which means automated texts are enabled. If the icon is gray, the system will send notifications as emails instead.
Under the hood, SMRT uses the Twilio Lookup Service to classify phone numbers automatically. The Twilio database can sometimes fail, especially with VoIP systems. The database could be wrong if a phone number was transferred from being a landline to mobile and vice versa. You can manually type a phone number into the Twilio lookup service to see details about a phone number. SMRT classifies phone numbers of type 'voip' and 'mobile' in Twilio as textable.