I self-host most of my infrastructure, but decided not to self-host outbound email

I've been self-hosting more and more of my applications, and one thing I kept running into was email. For things like: Password resets Account Verification Application notifications Alerts Background-job notification Transactional emails I initially considered running own SMTP server. But after looking into it, outbound email is a completely different problem from simply running an SMTP server. You have to deal with IP reputation, SPF, DKM, DMARC, Bounce handling, delivery tracking, retries, blacklists, provider blocks, etc. And even if the server itself is easy to deploy, getting consistent delivery to Gmail/Outlook/etc. is another story. I've ended up preferring this architecture: Self-host the application -> use SMTP/API for outbound email. The idea isn't to replace self-hosting. it's more like: Keep your application, database, queues and infrastructure under your control for the part of email that's painful to operate yourself. It provides both an API and SMTP, along with things like delivery logs, webhooks, bounce handling, automation, and a CLI. I'm curious what other self-hosters here do. Do you: Run Postfix/Mailcow/etc. yourself? Use SES? Use Mailgun/SendGrid/SMTP2GO/etc? Use your personal/business SMTP account? Something else? And those who have tried self-hosting outbound email, what was the biggest problem you ran into? I'm particularly interested in hearing about deliverability rather that just server setup.