We've been setting up email infrastructure using sendgrid on a dedicated IP. The domain it's emailing to is a new domain as well. We've got that domain set up with google apps and use it to send email to people without issue.

We did a mailing to a few select people on our new mail server. For the 20 or so people using gmail that received the mailing, those who had never received an email from colin @ newdomain had the email go to spam. Those who had received a message from colin @ newdomain had the email (from a different user) in their inbox. Anecdotally, it seems gmail highly values a previous email from that domain, but only for that one recipient.

Email is tricky. We're sorting through the issues of sending from a new IP and new domain. We're learning that email sending is like a credit score. No score is as bad as a crappy one.