At ExtraVM, we block various "throwaway" or temporary email or forwarding services as these are often used for malicious purposes. However, we also are forced to block some real email providers due to them mis-configuring their services, whether intention or not.
Blocked email providers:
- mailbox.org - This email provider blocks emails if the sender IP is on SpamCop blacklist. SpamCop is known to block Amazon Email Services (Amazon SES) IP addresses, even though Amazon is one of the larger email senders globally. This causes our emails to not be received by many Mailbox.org users.
Not blocked, but notes:
- Protonmail - We do not block Protonmail or Proton.me however Proton often rejects emails with generic responses that the receiver email account is blocked for a ToS violation. This may be due to the Proton accounts being newer and having restrictions, however it's a common issue. We suggest using another encrypted mail provider, if that's what you're specifically looking for.
