Always
try to avoid sending security-related email in clear text.
This is the Title of the Book, eMatter Edition
Copyright ?© 2007 O??™Reilly & Associates, Inc. All rights reserved.
2.3 What??™s Where in the Source | 49
2.3.8 The libmilter Directory
The sendmail folks have defined a mail filter API* called Milter. Using this API, thirdparty
programmers (you, for example) can design programs to access mail messages
as they are being processed by sendmail. Suchreal-time access allows email message
content to be filtered and possibly rejected based on content??”a potentially powerful
antispam tool.
The README file in this directory describes the steps needed to design, compile,
and run such a filter. But beware. The use of this API and creation of a filter program
require the use of POSIX threads. If your OS lacks POSIX thread support, you
will not be able to use this API.
For systems that support POSIX threads, we illustrate the creation and use of a mail
filter program in Chapter 26 on page 1169.
2.3.9 The libsm Directory
To support many of the new features in sendmail, and to pave the way for more
sophisticated versions in the future, the designers of sendmail decided to create a
replacement for many of the routines in the standard C library. A quick glance at the
libsm directory will reveal replacements, for example, of fput(3) and ungetc(3).
Pages:
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111