I run a website which needs to send the following emails:
- Sign-up email confirmation (required for access)
- Forgot password requests
- Change email address requests
- 2-factor enrollment requests
- Payment receipts
Previously, I simply had exim4 installed on the VPS and was sending email directly from there. However, in recent times, those emails were getting rejected by several large email providers (Microsoft and Yahoo) due to spam coming from adjacent IP address space.
Since I use Fastmail for the human emails originating from that domain, I configured the web application to use Fastmail SMTP credentials for sending those emails using my account there. That's been working great, until today, when I received an abuse report from Fastmail. They tell me that people have been marking the "Welcome to [website], please confirm your email address" as spam, and that I am not (no longer?) allowed to send automated email using their service.
So how does a small and low-budget website send (very small quantities of) email these days?