set up FQDN (fully qualified domain name) for sendmail ------------------------------------------------------ A box behind firewall, has a faked hostname, e.g: [root@raider mail]# hostname raider.its.unimacq.edu.au [root@raider mail]# cat /etc/hosts # Do not remove the following line, or various programs # that require network functionality will fail. 127.0.0.1 localhost.localdomain localhost 192.168.1.1 ipcop When you send mail to someone, their mail server returns: ... ----- Transcript of session follows ----- ... while talking to mail.iinet.net.au.: >>> MAIL From:<terrence@xxxxxxxxxxxxxxxxxxxxxxxxx> <<< 553 sorry, your envelope sender domain must exist (#5.7.1) 501 5.6.0 Data format error [-- Attachment #2 --] [-- Type: message/delivery-status, Encoding: 7bit, Size: 0.3K --] Reporting-MTA: dns; raider.its.unimacq.edu.au Received-From-MTA: DNS; localhost.localdomain Arrival-Date: Mon, 19 Jan 2004 14:21:50 +1100 ... Add hostname alias (raider.its.unimacq.edu.au) for firewall box (igloo.its.unimacq.edu.au) to solve the problem [root@raider mail]# nslookup raider Note: nslookup is deprecated and may be removed from future releases. Consider using the `dig' or `host' programs instead. Run nslookup with the `-sil[ent]' option to prevent this message from appearing. Server: 137.111.201.5 Address: 137.111.201.5#53 raider.its.unimacq.edu.au canonical name = igloo.its.unimacq.edu.au. Name: igloo.its.unimacq.edu.au Address: 137.111.20.252 [terrence@raider terrence]$ less .muttrc ... set hostname="localhost.localdomain" ... |