Can't receive mail - ISPConfig / Postfix

[stormalx]

I have installed CentOS, LAMP, ISPConfig, etc. All seems OK, SMTP working fine. However... I can't receive any mail. According to ISPConfig the POP3 server is running fine. When I send an email to either wwwX_user@domain.com or user@domain.com I get the below error emailed straight back... what am I doing wrong!?

This is the mail system at host localhost.localdomain.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to <postmaster>

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

The mail system

<web3_test@localhost.localdomain> (expanded from <test@adrianwestaway.com>):
critical OS file missing. Command output: procmail: Error while writing to
"/dev/null"

Final-Recipient: rfc822; web3_test@localhost.localdomain
Original-Recipient: rfc822;test@adrianwestaway.com
Action: failed
Status: 5.3.0
Diagnostic-Code: x-unix; procmail: Error while writing to "/dev/null"

[stormalx]

OK I figured it out. I assumed that there wasn't actually a "critical OS file missing", so if it couldn't write to /dev/null it was probably permissions. So I changed permissions to 666 for /dev/null and it works fine now.

So my question now is, what are implications of setting /dev/null to 666? It's basically a black hole yes? So doing this won't affect security? Excuse my ignorance, but I'm newish to Linux...

[falko]

It's 666 on my system as well, so it seems to be ok now. :)