Seeing lots of wrong answers here, though I can’t guarantee I’ll be any more accurate. But I have a feeling this has to do with how ente.io’s email egress is set up.
They have three email origins provided (all from Zoho): Zoho, ZCsend, and TransMail. I would expect that Zoho is for support and business email, ZCsend is for marketing, and TransMail handles transactional emails such as billing and password resets. That said, I only see a domain key for Zoho attached to their ente.io domain. This means when Gmail’s SMTP servers might not be able to successfully authenticate the email’s origin if it’s sent through ZCsend or TransMail, leading them to take the default action of marking spam for an unauthenticated marketing-/phishing-esque email.
TL;DR Google most likely isn’t doing this intentionally, but rather ente.io’s email service might not be configured the best and Gmail is unable to distinguish it from what it considers spam as a result.