Google apps or a local server like Postfix relaying outgoing email through a service such as AuthSMTP. Deliverability is a PITA otherwise. You have to jump th

Google apps or a local server like Postfix relaying outgoing email through a service such as AuthSMTP. Deliverability is a PITA otherwise. You have to jump through a bunch of hoops to get email providers to accept your email if using a dedicated solution (including VPS) and if it's a shared server then you are at the mercy of other users who could be spamming people from the same IP and get it blacklisted.