Also note that it's super easy to configure postfix (and likely others) to send all outbound email via a third party service.
I personally use smtp2go.com, and was on their free tier for ages (now upgraded via work). Can recommend, as it "just works" and avoids all the mucking around with SPF/DKIM/etc.
Oh, on a similar note, definitely avoid Sendgrid if you want to send email via a third party. They're outright blocked (as a spam source) by way too many places to be considered reliable any more. :(
I personally use smtp2go.com, and was on their free tier for ages (now upgraded via work). Can recommend, as it "just works" and avoids all the mucking around with SPF/DKIM/etc.
Oh, on a similar note, definitely avoid Sendgrid if you want to send email via a third party. They're outright blocked (as a spam source) by way too many places to be considered reliable any more. :(