Getting error as ” Sending unsolicited email ” while sending Group Mails

Error: 

Sending unsolicited email

Solution: 

The issue is due to sending unsolicited email to an email id DDDDDDDDDDD which is not subscribed to your mailing list. Sending mails to unsubscribed email ids, will result in your ip getting blacklisted. Also your ip reputation lowers. We advise you to check your mail database and remove emails that are not subscribed to you. Also remove the emails in the above abuse log immediately and avoid sending to them again.