Sendgrid, Mailchimp are email services. They them-self don't provide the content. Where as Bit of News is a news services that relies on email. And yes emails

Sendgrid, Mailchimp are email services. They them-self don't provide the content. Where as Bit of News is a news services that relies on email. And yes emails are unstable, especially with the way Gmail handles them / attempt to segregate different types of emails.