Spam emails is unsolicited and unwanted junk email sent out in bulk to an indiscriminate recipient list. Typically, spam is sent for commercial purposes. It can be sent in massive volume by botnets, networks of infected computers.
Practices to avoid server IPs from sending Spam Emails
Temporary stop sending email:
- stop sending email (e.g. stop all mail software such as qmail, Postfix, Sendmail etc.)
- check the email queue (e.g. qmHandle for qmail, postqueue -p for Postfix)
- analyse your logs using the Message ID Or Destination IP found in the block alert.
Reserve IP Better choice to avoid marked as Spam Emails:
- reserve an IP block dedicated solely to email usage
- configure reverses on all IPs correctly.
This operation will enable you to simultaneously isolate the IP and domain reputation if you send emails for various domains, to receive the complaints, and thus do what is necessary to get unblocked by various organization.
Analyse Email Content:
Understand technical aspects Request For Comments (RFC)
RFCs (Request For Comments) are documents intended to describe technical aspects of the internet. They are produced and published by the IETF (Internet Engineering Task Force), a group which basically produces and defines standards. For more information, see: RFC, IETF and Internet Draft. Best practices are recommended methods which are often based on these documents and are intended to advise you on the best way to proceed. In this instance, this means the basic rules to follow so that your emails are not marked as spam.
Authentication to protect reputation
Enable Some authentication services to protect IP and service reputation.
- Sender-ID :An email authentication technology developed by Microsoft which validates the authenticity of your domain name by verifying the IP address of the sender. This technology is based on the IETF standard: RFC4406
- SPF : Sender Policy Framework is a standard for verifying the domain of the sender. It is based on RFC4408 and consists of adding an SPF or TXT field to the domain DNS, which contains the list of IPs authorised to send emails from this domain.
- Reverse DNS : Reverse enables your IP to be “translated” into your domain. That allows the domain associated with the IP address to be found.
- DKIM : DKIM This standard is described in RFC4871.
AOL, Google (Gmail) work on this basis. Official website: DKIM