Why broadcast emails are not delivered?

Hey Natella,

I would have a few folowup questions regarding this:

1. Have you check this via a spam testing tool, such as https://mailchecker.net/ ?
2. Have you set the DNS records for SPF and DMARC?
3. Is this the first time you experiencing this / Is this your first broadcast you sent out?

A few things to add on top of what’s already been said:

1. If there are a lot of google based inboxes in your database, I suggest getting Postmaster Tools setup, it’s the only way to get feedback about spams and IP reputation from Google inboxes. https://www.gmail.com/postmaster/
2. Authentication is a big thing, and I concur with @Felix. SPF and DKIM at a minimum. DMARC is also a good idea but sometimes IT teams don’t like setting a strict policy like reject. 
3. If you’re a new account, you have to warm things up, which essentially means taking things slow enough and showing good email sending behavior so that inbox providers don’t think you’re a spam sender. So start with small segments, send messages that users are expecting (like getting a welcome email in place), and overtime things should improve.