ezmlm-reject(1) will look for DIR/msgsize, DIR/mimereject, and DIR/mimeremove if the ‘DIR’ argument is specified (‘DIR’ can be left out to conserve resources on lists that do not use these features). Note: The ‘DIR’ argument is also required for the the To:/Cc: list address restriction (see Requiring the list address in headers). If the message contains MIME parts that are of a content-type listed in DIR/mimereject they are rejected. If the message is a simple MIME message of a content-type listed in either DIR/mimereject or DIR/mimeremove it is also rejected.
There is currently no ezmlm-make(1) switch for DIR/mimereject, but it can easily be configured by editing ezmlmrc(5). The ezmlm-make -x switch configures DIR/mimeremove (see Removing MIME parts from messages) for a list of content-types). Messages consisting solely of these content-types (rare) will be rejected, and the corresponding MIME parts of composite messages will be removed.