E-Mail submission to all major providers and relay services (Gmail, Microsoft 365, Yahoo, iCloud, Amazon SES, SendGrid, Mailgun, …) works on ports 587 / 465 / 2525

To prevent spam and abuse, direct outbound SMTP (port 25) is blocked on our network from all r64 ips. Authenticated mail submission to all major email providers and relay services is fully supported now — simply use your provider's submission server on port 587 (STARTTLS) or 465 (SSL/TLS); relay/ESP services may also use 2525.

Now reachable:

Mailbox providers: Gmail, Outlook / Microsoft 365, Yahoo, Apple iCloud, QQ, NetEase (163/126), Mail.ru, Yandex, Naver, GMX, web.de, T-Online
Relay / ESP services: Amazon SES, SendGrid, Mailgun, Postmark, SparkPost, Mailjet, Brevo, SMTP2GO, Elastic Email, Mandrill