It doesn't matter if it is a hosted service or if its just your local mail transfer agent, every "SMTP mailer" works the same way. There are lots of ways to sen

It doesn't matter if it is a hosted service or if its just your local mail transfer agent, every "SMTP mailer" works the same way. There are lots of ways to send email that don't involve a locally administered SMTP mailer (such as an API which indeed has a connection string to a hosted service) but none would be described with that term.