A Pinger in the context of anonymous remailers is a program that regularly sends messages through remailers to determine their status. Based on the responses, the Pinger calculates reliability statistics which may be used by remailer clients to choose a chain of remailers to use.

Furthermore, Echolot collects configuration parameters and keys of remailers and offers the collected information in a format readable by remailer clients. This helps reduce the administration effort required to use or host remailers.