Filter described here is filter system for articles posted to ML. This filter is implemented as FML::Filter class.
Other than article filter, there may be command mail filter. FML::Filter does not provide such function. Instead, FML::Command::Filter class provides command mail specific filter e.g. line length limit of one line.
There are three types of filter system for content check such as for header, body and mime structure based. Other than the tree cases, we should consider text/plain and non mime text (text/?) filter. So there may be four types of filter.
header body non-mime permit / reject (!MIME of 4.0's content filter) mime component filter 4.0's content filter text/plain filter ja, en, ... (language dependent) language independent (e.g. M$ GUID scanner) check of the first text/plain part syntax check external filter (call external virus/spam checker) clamav spamassassin bogofilterOther than these filters, content_filter using SMTP/LMTP can be needed but not implemented. If you need content_filter, please use the function of Postfix.
Traffic based filter is also needed but not implemented yet.
Copyright (C) 1993-2018 Ken'ichi Fukamachi mail:< fukachan at fml.org >