Mailgun has rejected me after 8 years of usage because my initial payment in 2015 was from a Russia-issued bank card. Really dumb.
Amazon SES has rejected me for an unknown reason.
- Notifications for my forum users.
I have multpile forums, particularly:
https://mage2.pro
https://df.tips- Work emails from my admin@mage2.pro, admin@df.tips and other addresses.
Visitors register on my forum themselves.