1. sending mail cc/bcc'd to large numbers of recipients
2. Similar mails have been marked as spam by lot of users
3. Using outlook and your IP is blacklisted by lot of Anti SPAM engines.
4. Domain is blacklisted
2. Similar mails have been marked as spam by lot of users
3. Using outlook and your IP is blacklisted by lot of Anti SPAM engines.
4. Domain is blacklisted
Resolution
1. Try to send to specific and few people
2. Change the subject and body then try
