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How do I bind Postfix MTA to specific IP address such as or


Q. My mail delivery fails with DNS: Service unavailable error. How do I fix this error under Linux / UNIX operating systems?


Q. How do I configure my Postfix mail server to scan incoming mail for spam using DNS Blackhole List such as: a) The Spamhaus b) Open Relay Database etc A. To discard spam or garbage email you can use 3rd party services such as Spamhaus. These are realtime database of IP addresses of verified spam […]


Q. How do I block all PDF or ZIP files attachments under Postfix Mail Server? A. You can easily block email attachments using mime header check. Open postfix config file Login as the root, enter: # vi /etc/postfix/ Block zip or pdf files Use mime_header_checks postfix config directive, enter: mime_header_checks = regexp:/etc/ostfix/block_attachments Save and close […]


Q. How do I configure Dovecot IMAPS and POP3s server using SSL certificate? Can I use SSL certificates generated for Postfix mail server? A. Dovecot is an IMAP server for Linux/UNIX-like systems, written with security primarily in mind. It also contains a small POP3 server. It supports mail in either of maildir or mbox formats. […]

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Q. I’m running Redhat Enterprise Linux 4.5 server along with Postfix and Cyrus mail server. However I’m getting following error in my log files: Jun 10 18:00:04 server postfix/smtpd[7280]: sql_select option missing Jun 10 18:00:04 server postfix/smtpd[7280]: auxpropfunc error no mechanism available How do I fix this error? I’m not using mysql for postfix. A. […]


How do I find out my DNS Server Addresses under Linux / UNIX / Windows operating system? What is my dns server IP address under Windows operating systems? Can you specify a list of public DNS server for personal use?