Hi Raju,
We followed that article and it still did not work. That's why I was hoping for other ideas.
1. Create clean, collaborative, and responsible content
We did this and confirmed, using the Marketing feature, that our SPAM score is very low
2. Authenticate your sending domain
This was completed.
3. Avoid sending to invalid and inactive email address
We are testing to only 1 address
4. Don't use purchased or rented mailing lists
We are testing only 1 address
5. Send consistent volumes
Does not apply, testing an email
6. Set up DKIM for your sending domain
Same as #2 above - we authenticated the sending domain
