postfix smtp Must issue a STARTTLS command first
When sending an email to a server, mail bounced with the following error message. Action: failed Status: 5.7.0 Remote-MTA: dns;
How to stop SPAM with Postfix RBL
To stop spam using RBL in postfix, edit main.cf vi /etc/postfix/main.cf Add smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, reject_invalid_hostname, reject_unauth_pipelining, reject_non_fqdn_sender,
install postfix from source code
Requirements yum -y install db4 db4-devel Create user groupadd postfix -g 1000 useradd postfix -u 1000 -g 1000 groupadd postdrop