May 26, 2018
Local mail delivery agent
The procmail mail processing program can be used to create mail-servers, mailing lists, sort your incoming mail into separate folders/files real convenient when subscribing to one or more mailing lists or for prioritising your mail, preprocess your mail, start any programs upon mail arrival e.g. to generate different chimes on your workstation for different types of mail or selectively forward certain incoming mail automatically to someone.
Procmail can be used - and installed by an unprivileged user for himself only. - as a drop in replacement for the local delivery agent /bin/mail with biff/comsat support. - as a general mailfilter for whole groups of messages e.g. when called from within sendmail.cf rules.
The accompanying formail program enables you to generate autoreplies, split up digests/mailboxes into the original messages, do some very simple header-munging/extraction, or force mail into mail-format with leading From line.