无法在 Digital Ocean 上发送邮件

Mariano, I am using default port 586. This is the new account with DO.

I have main domain on Inmotion hosting - www.example.com and have email account admin@example.com. Have the inmotion settings for this email accounts.

I have created sub domain as forum.example.com this is redirected to digital ocean. Don’t have any SMTP settings on DO.

Any suggestions from experts ?