> I find it hard to believe that you can "free-ly" send e-mail to, say, 100,000 e-mails and actually have it get delivered at a high rate? I would love to learn

> I find it hard to believe that you can "free-ly" send e-mail to, say, 100,000 e-mails and actually have it get delivered at a high rate? I would love to learn if I'm wrong though. The company I work for has an outbox feature which supports this and it was a non-trivial problem to solve. We ended up using sparkpost with a bunch of modifications to isolate potentially bad actors (i.e., clients who pay for our software but send what is basically spam) to an individual sending pool. We also have CSMs that handle this and help to coach clients to not send spam. https://support.sparkpost.com/docs/deliverability https://support.sparkpost.com/docs/deliverability