...Shows HTML, Plain Text and Source version of messages, as applicable. Rewrites HTML enabling display of embedded, inline images/etc and opens links in a new window. Command-line options to override the default SMTP/HTTP IP and port settings. Mail appears instantly if your browser supports WebSockets, otherwise updates every thirty seconds. Sendmail-analogue command, catchmail, makes using mailcatcher from PHP a lot easier. Encodings are difficult. MailCatcher does not completely support utf-8 straight over the wire, you must use a mail library that encodes things properly based on SMTP server capabilities.