Sisimai is the system formerly known as bounceHammer 4, is a Perl
module for analyzing bounce mails and generate structured data in
a JSON format (YAML is also available if "YAML" module is installed
on your system) from parsed bounce messages. Sisimai is a coined
word: Sisi (the number 4 is pronounced "Si" in Japanese) and MAI
(acronym of "Mail Analyzing Interface").