I have a failover setup for my main internet provider using an LTE modem. I've also found it very useful to have a mobile number available for sending SMS alerts when server errors occur, such as:

• no internet connection — sending status updates about the failover
• sending messages about modem restarts
• and so on...

Usage:

sms <option> [arg] [argX]...

send [number] [text]    - send message
ls                      - show messages
read [number]           - read sms num X
del  [number X]         - delete sms X, if not given ALL!
all                     - show ALL smseses