---

---

Comments and suggestions concerning this book should be mailed to gmourani@videotron.ca © Copyright 1999-2000 Gerhard Mourani and Open Network Architecture ® 261 The mailertable & mailertable.db files A mailertable is a database that maps “host.domain” names to special delivery agent and new domain name pairs. With this feature mail on your network can be delivered through the use of a particular delivery agent to a new local or remote domain name. · To create the virtusertable, domaintable, mailertable, and their corresponding “.db” files into “/etc/mail” directory, use the following commands: [root@deep /]# for map in virtusertable domaintable mailertable > do > touch /etc/mail/${map} > chmod 0644 /etc/mail/${map} > makemap hash /etc/mail/${map}.db < /etc/mail/${map} > chmod 0644 /etc/mail/${map}.db > done The “/etc/sendmail.cw” file for the Central Mail Hub The “/etc/sendmail.cw” file is read to obtain alternative names for the local host (in our example, the Central Mail Hub Server). One use for such a file might be to declare a list of hosts in your network for which the local host is acting as the MX recipient. Also note that “sendmail.cw” file is required only on server that receive, forward and send mail to the out side network like the Central Mail Hub Server. On that machine we simply need to add the names of machines for which it (i.e. mail.openarch.com) will handle mail to “/etc/sendmail.cw”. Here is an example: Create the sendmail.cw file (touch /etc/sendmail.cw) and add the following line: # sendmail.cw - include all aliases for your machine here. openarch.com  deep.openarch.com  www.openarch.com  win.openarch.com  mail.openarch.com  With this type of configuration, all mail sent will appear as if it were sent from “openarch.com”, and any mail sent to “www.openarch.com” or the other hosts will be delivered to “mail.openarch.com” our mail Hub. Please be aware that if you configure your system to masquerade as another any e-mail sent from your system to your system will be sent to the machine you are masquerading as. For example, in the above illustration, log files that are periodically sent to root@www.openarch.com by the cron daemon of Linux would be sent to root@mail.openarch.com our Mail Hub. The “/etc/null.mc” file for the local or neighbor client and server machines Since our local clients machines never receive mail directly from the out side world and send, relay all their mail through the Mail Hub server, we will create a special file called “null.mc”, which, when later processed, will create a customized “sendmail.cf” configuration file that respond to this special setup for our neighbor or local server client machines. This m4 macro file is simple to create and configure because it don’t need lot features like configuration file (sendmail.mc) for the Central Mail Hub server. Step 1 Create the null.mc file (touch /etc/null.mc) and add the following lines: divert(-1) dnl This is the macro config file used to generate the /etc/sendmail.cf