On Google, the emails in the spam folder should give a description of why they’re in the spam folder. What does Google say about the emails you’re sending?
Regarding reverse DNS – it is a good idea to set that up, though that’s actually something you’d have to get your ISP to set for you.
They often provide a web form to handle that, though if they don’t provide a way to do that online, you could always give them a call and they should be able to help you out on the phone.
Hello Eric,
There several reasons according Google.
They can’t check the identity of the sender, Phishing mails and so on.
I will search the internet for possible solutions.