[cobalt-developers] RFC1893 4.4.X Codes When Sending Mail to Qube3

["Paul D'Alessandro" <pmd@xxxxxxxxx>]

I am encountering persistent "DELIVERY FAILURE: Enhanced Mail System Status
Code (RFC1893):4.4.X" where x=1 or 7 upon sending mail to my Qube.  If mail
is sent to one user on the Qube from another via the webmail client, it
works just fine.  Additionally, my Outlook Mail client works just fine
trying to retrieve mail.  This problem has been repeated from numerous
outside mail clients/accounts and is consistent.  The Qube functions
properly for all other IP traffic.  My domain is set up as www.domain.com
(domain.com example of actual domain name), the MX entry with my ISP's DNS
points domain.com mail to www.domain.com.  I have enabled only IMAP and POP
servers (not the SMTP server function) with advanced settings as follows:

Delivery Schedule: Immediate
Maximum Email Size: 15mb
Force Sender's Domain: empty
Smart Relay Server: empty
POP Authenticated Relaying: not checked
Relay Email From Hosts/Domains/IP: empty
Receive Email Addressed To:  domain.com, www.domain.com, mail.domain.com
Block Email From Hosts/Domains: empty
Block Email From Users: empty

I have scoured the postings in this list and believe I have everything
correctly, but obviously I am not.  Any help would be greatly appreciated.

Paul D'Alessandro