Recommended settings

From ASSPSMTP

1. Enable Delaying - this will stop a majority of spam attempts in their tracks by forcing the sending system to perform a time-delayed retry for resending the message. "Zombie" systems that are part of spamming botnets cannot handle queuing and retrying.
   • The default settings for Delaying are usually recommended for most users however it is advised to enable "Enable Delaying logging" for troubleshooting.
2. Enable HELO validation - this will allow you to block spam that is from a non-authentic source, by scrutinizing the the beginning of the SMTP session for signs of an illegitimate source.
   • This setting is labeled "Validate Format of HELOs" and is located under the "Validate Sender" section.
   • A value of 1 is recommended for most installs.
3. Enable SPF - this will allow you to blocked forged e-mail from domains that publish SPF records. Using this can put a dead-stop to spoofed e-mail appearing to come from sources such as PayPal, eBay, and many banking institutions.
4. Enable DNSBL (aka RBL) - this will allow you to block e-mail from known spammers that have already been reported.
   • For a list of recommended DNSBL providers please see the DNSBL page.