Cloud hosting: transactional emails

For me the first "obvious" point where I moved away from self hosting too much was email, specifically delivering transactional emails.

In the traditional world of running things myself I'd have a server with postfix and sendmail running locally, probably it was even serving as the MX for the domain in question just as much as it was hosting the corresponding app or website. This generally worked great until you notice some points where it doesn't mix well with the reality on some VPS providers:

• Depending on what other people are doing the IP reputation of you system may not be as stellar as it should be.
• Have you ever also hosted someones wordpress site on your server? Do you actually know that they keep everything up to date and secure? If that wordpress instance starts sending out lots of emails over night the reputation of your IP may also be gone.
• Last but not least: once you host things beyond your own hobby project this question of deliverability then becomes something where you'll get questions about emails that haven't arrived and each time you'll be researching, no knowing if there is an issue or someone just hasn't seen the email.

An additional point for me came when I started moving away from traditional VPS providers and to companies like Hetzner or AWS: the reputation issues may not exist - but that's because by default they will block you from sending outgoing email per their firewall settings. While you can ask for this to be opened for you, it's probably a good pointer that there may be something to the idea of transactional email services. With all this in mind I've become a happy user of postmark as I like their UI for managing everything and am happy with the emails being delivered reliably. Additionally they do support inbound emails and I can set up webhooks for events like emails that could not be delivered.

There are also a whole host of other providers, so there is something in it for everyone.