1. Creating a good IP reputation takes time, get a static IP from your ISP and gradually increase number of sent out emails. 2. Having multiple IP addresses an

1. Creating a good IP reputation takes time, get a static IP from your ISP and gradually increase number of sent out emails. 2. Having multiple IP addresses and throttling helps if you send bulk emails. 3. Check email headers of spammed emails, they usually contain valuable info about the reason of being detected (SPF/DKIM ,...) 4. Check the contents of your emails and find out spam score of the content. 5. You can look into commercial solutions like: www.own-mailbox.com 6. Hillary, if it's you, don't do it again!