Open resolver issues with Spamhaus – how to check
Using a public name server such as 1.1.1.1 or 8.8.4.4 has become the norm, but if you’re running an email server, this may lead to
5.7.1 Your access to submit messages to this e-mail system has been rejected. Talos Intelligence Cisco Bullshit
The new kid on the block with their opaque error messages in so called “spam protection” is Cisco Talos Piece of Shit Intelligence. If you
Advanced Postfix Troubleshooting using -vv flags in master.conf
Synopsis Client’s Virtualmin server failing perpetually with: dsn=5.1.1, status=bounced (User unknown in virtual alias table) Client mucked about with the standard config. mc -e /etc/postfix/virtual
Postfix crashes due to lost IPv6 configuration and Postgrey dependency in Virtualmin
At times, Postfix may crash with many errors in the log file, for example: 2025-07-15T12:59:50.620961+02:00 server postfix/smtpd[2243195]: warning: problem talking to server 127.0.0.1:10023: Connection refused
Post WHM/cPanel Transfer tool, there and back again, emails are being forwarded to old SMTP via proxy
The WHM transfer tool is incredibly powerful. It allows one to easily migrate a domain between two servers, with zero downtime and including DNS updates.
New Outlook failing on outgoing
Microsoft just took over your PC with new Outlook. Now outgoing is failing. You’re using cPanel. Here are some of the errors: We couldn’t deliver
Wrong SSL certificate interfering with Outlook and Virtualmin IMAP/SMTPS
This morning an old established client tell me he has been getting certificate warnings, and lately a lot of problems sending email. After some time
Repeating ‘received a response that is not DNSSEC validated’ messages on a fresh Virtualmin Ubuntu 22.04 server
You might see these repeating messages on a newly perfectly installed Virtualmin server: Jun 1 06:44:36 host postfix/smtp[104754]: warning: reason: dnssec_probe ‘ns:.’ received a response
Proxmox Mail Gateway Quick Start Guide
Introduction Writing a quick start article for an anti-spam gateway is not trivial. The fact of the matter is everyone’s idea on how to use
Mac OS X El Capitan can’t send messages on port 465 SSL nor 587 STARTTLS
Welcome to old operating system support! In today’s edition you’ll find older operating systems don’t work properly with modern and secure and up to date