I run an email based service and while I send most email on my own I have been using the following providers for fall-back (for inbox providers that have very s

I run an email based service and while I send most email on my own I have been using the following providers for fall-back (for inbox providers that have very strict policies). - https://serversmtp.com/ https://serversmtp.com/ - https://aws.amazon.com/ses/ https://aws.amazon.com/ses/ I prefer SES for a number of reasons: - The price is about the best you will get. - You can DKIM sign messages yourself if you want (although IIRC they remove the ability to verify your domain with DKIM from the console recently. Hopefully they don't drop this support). - Pay as you go Pricing means that you don't pay for unused quota. - Regional service may be more complicated but in theory you should be able to tolerate localized issues. The main downside is that you need to verify in each region which is very annoying.