Why a legitimate sender is being marked as spam?
Our cpanels come with SpamAssassin to identify spam using several methods including text analysis, internet-based realtime blacklists, statistical analysis, and internet-based hashing algorithms. Using its rule base, it uses a wide range of heuristic tests on mail headers and body text to identify “spam”, also known as unsolicited bulk email. Once identified as spam, the mail can then be tagged as spam for later filtering using the user’s own mail user agent application or at the mail transfer agent.
If your sender is legitimate and still being tagged as “spam” then you can view headers of that email to investigate under headings of “spam score” and “spam report” that will explain why this email marked as spam. If you find it difficult going into headers information then you can forward the headers information of the message and we will explain you that why it was marked as spam.
NOTE: If you want to mark your sender as “NOT SPAM” and wish to receive all future emails without spam in subject then watch the following video.
www.youtube.com/watch?v=FGSU22CJvH8
SpamAssassin is an excellent tool to control the incoming spam and If you want to read more about SpamAssassin then follow below link.
https://cwiki.apache.org/confluence/display/SPAMASSASSIN/SpamAssassin