OS X Lion postfix smtpd problems

Question

For the life of me I couldn't get smtpd running correctly on my iMac (brand new SL iMac upgraded to Lion).
Looking at the syslog, I kept getting:
postfix/smtpd[1001]: fatal: open /etc/postfix/submit.cred: No such file or directory
postfix/master[971]: warning: process /usr/libexec/postfix/smtpd pid 1001 exit status 1
postfix/master[971]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling
Upon checking, that /etc/postfix/submit.cred file was missing. Created a blank one. Syslog then showed:
postfix/smtpd[1041]: fatal: unsafe ownership or permissions on /etc/postfix/submit.cred: uid/gid/mode are 0/0/644 should be 0/0/0600
postfix/master[1035]: warning: process /usr/libexec/postfix/smtpd pid 1041 exit status 1
postfix/master[1035]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling
Did the chmod 0600 on it.
FINALLY smtpd started accepting connections!
Syslog still showed a warning:
postfix/smtpd[1420]: warning: no valid hostport|username|password entries in /etc/postfix/submit.cred
So I just commented it out of /etc/postfix/main.cf:
# (APPLE) Credentials for using URLAUTH with IMAP servers.
#imap_submit_cred_file = /etc/postfix/submit.cred
And now all looks good.
Seems this is a new (broken?) option Apple have added to postfix.
Hope this helps someone else avoid the frustration I've been having!!  :-)

Answer 1

Hi, the submit.cred file is NOT a new (broken) Apple option. It has been introduced, instead, with the new versions of PostFix, so you could find it also on Linux or BSD installatios running the latest version of it.
It has been introduced to match the MTA with the RFC4468 (http://tools.ietf.org/html/rfc4468) which describes an extension of the IMAP protocol.
In order to fix the problem your console is displaying, you should:
Create a submit.cred file in /etc/postfix directory (sudo touch /etc/postfix/submit.cred will do).
Create a header for that file: sudo echo "submitcred version 1" >> /etc/postfix/submit.cred
Add as many lines as the number of users you want to enable to submit mail, in the form hostname|user|passwd sudo echo''hostname|username|password" >> /etc/postfix/submit.cred
Give the file the appropriate permissions: sudo chmod 600 /etc/postfix/submit.cred
Once you've done this you could restart postfix and everything sould run smoothly. You should also fine-tune your postfix configuration in order to prevent it to deliver spam or provide security breaches.
Enjoy.