Nixle Nixle is messaging system that allows users to customize how (text, email or web) they receive messages, as well as the type of messages (alert, advisory or general) they receive. Users can also specify multiple geographical areas they are interested in. For example, if you live in Monterey Park and work in Los Angeles, you can sign up to receive messages from both the MPPD and the LAPD. Nixle is also encouraging other agencies, such as school districts, to participate. Please visit and register on the Nixle website for more details and other examples.