content: Not to mention Gmail has some of the most aggressive anti-spam filters around.  If the email is from a new domain that isn't very popular yet and/or it contains a lot of buzzwords (like I imagine a Trump email would) like Ads usually do, they toss it in the spam folder. Once enough people white-list the domain it's coming from, it will likely not be tripped as spam any more.    People forget that sending email is a little bit more complex than they think.  Try setting up your own mail server some time.  Assuming you manage to do everything right, people will probably still not receive your emails no matter what provider they use because you'll almost certainly be marked as spam with your who-the-fuck-is-this domain name.