14)
?§26.6.13 on page 1223 The Milter xxfi_unknown() function is used to review unknown SMTP commands (8.14)
This is the Title of the Book, eMatter Edition
Copyright ?© 2007 O??™Reilly & Associates, Inc. All rights reserved.
1248
Appendix C APPENDIX C
The checkcompat( ) Function
Inside sendmail is the often-overlooked checkcompat( ) routine. It has existed since
V3, and is intended to allow the site administrator to accept, reject, and log mail
delivery attempts. As sendmail continues to evolve, the need for this checkcompat( )
routine diminishes. It is no longer, for example, needed to screen for spam rejection
because much of that can now be done in rule sets and the access database. On modern
machines that support POSIX threads, the Milter API allows external programs
to perform all the tasks that formerly could be handled only by the checkcompat( )
routine.
But the checkcompat( ) routine still has a number of uses. Here are a few:
??? Capture the message body for each outbound message and send it via TCP/IP to
a central archive host. Be sure to detect multiple recipients to avoid duplicate
archived messages.*
??? Check the Received: headers on messages sent from one of your MX servers to
see who sent it. This allows you to reject spam messages that try to do an end
run around your access database. Sort the Received: headers by date and examine
the second most recent.
Pages:
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241