SMTP以外の方法で電子メールサービスに接続する代替手段はありますか（Digital Oceanで）

[Denis_Didkovsky (DenisD)]

this is not the solution for us as they didnt respond to the ticket

DigitalOcean blocking SMTP and forcing SendGrid usage

Definitely good advice, and thank you for it. However, DO’s offerings plays quite nicely with some other things I’m building and trying to connect without hassle, so it’d be wonderful if they didn’t pull such sketchy moves. Nearly any Ubuntu server could — in theory — work just fine so your point is completely valid.