> Let me tell you a secret: Big Mailer Corps are not worried about you but are worried about big senders harassing their users. They do not care about your personal server sending a few mails, even if its in the thousands per months. What they care about is the infected computers or compromised servers flooding their users. What they care about are the marketing companies that are literally shitting over them, sending individually millions of commercial mails per day, trying to work-around spam filters, and that sometimes manage to go for a while without being rejected. Unless you are sending hundreds of thousands of mails to them on a daily basis, quite frankly and without trying to hurt your feelings, you fall waaaaaaaaaaaaaaay below the radars.

This is absolutely not true. A server I had mailed out daily run outputs to local users, and was also configured to send an email to one of the users' gmail accounts. I also used that server for personal email, but eventually had to stop because the daily run outputs got us blocked by gmail.