Sending a million emails per month

Pacopag

Hi. I’m building an app that is very much centered around email. As email (and other notifications) is at the heart of the app, I feel like the smtp server should be something self hosted that we control.

I’ve used mailcow personally, and always loved it. But now I’m planning on sending roughly a million emails per month from the app (my personal mailcow server sends only a few per month, so it’s not the same ball game). It’s probably important to know that almost all these emails will be destined to registered users.

I’m a devops engineer professionally, so I’m not afraid of the administration part, but I’m definitely not an email expert, as I’ve always delegated the sending part to ses or mailgun.

Here are my concerns about running a self hosted postfix.

There are warnings all over the blogs that IP reputation is hard to build. How hard is it really?

I’m not familiar with how to horizontally scale postfix. Or would I even need to? I read that even a single instance on modest hardware can send like crazy, and I’m pretty sure I could set up reliable storage volume and self healing (via scaling group in ec2).

Am I crazy, and should just go with ses or similar?

Any other comments on the things I’m sure I’m missing would be great to hear to.

tankerkiller125

Pacopag There are warnings all over the blogs that IP reputation is hard to build. How hard is it really?

This can be very hard to do properly. It takes months of work and one false step can get you on a blacklist that’s very hard to get off of.

Pacopag Am I crazy, and should just go with ses or similar?

You can build something yourself here, but my personal recommendation as someone who works for a company that sends thousands of emails a week I would recommend offloading this kind of thing to people who work with emails for a living.

Pacopag

Thank you for your reply. I’ve already gone ahead and setup SES, because it is easy and cheap (the most painful thing with SES is setting up decent logging).

I think I might someday set up a homegrown mailserver, and use it only for a subset of ‘trusted’ users, that I hope will explicitly unmark anything that goes to spam, just to keep playing with the idea.