Disclaimer: Private.Ki uses Realtime Blackhole Lists (RBL)

Private.Ki uses Realtime Blackhole Lists (RBLs) to protect our users and infrastructure from spam and abuse. This applies only to outgoing, non-encrypted external emails sent via SMTP. Internal messages and encrypted communications are not affected.

Why we use RBLs

Spam is harmful to recipients, dangerous for our infrastructure, and undermines trust in secure communication. Allowing spam from our system would put all users at risk, including delivery issues, blacklisting, and abuse of Private.Ki services. 

As outlined in our anti-spam policy, we do not support spam and actively prevent it.

Using RBLs is a standard and necessary measure to ensure that Private.Ki cannot be used as a platform for spam, phishing, or malware distribution.

When RBL checks apply

RBL checks are performed only in the following case:

  • Outgoing emails sent to external, non-Private.Ki recipients

  • Emails that are not encrypted and are delivered via standard SMTP

This means RBL checks apply only when an email leaves the Private.Ki system in plaintext form so it can be read by a regular external email provider.

What is checked

For eligible outgoing SMTP messages, we extract:

  • IP addresses contained in headers or message content

  • Domains and Links (URLs) contained in headers or message content

These elements are checked against one or more RBL providers to determine whether they are associated with known spam, phishing, malware, or abusive activity. If a match is found, the message may be blocked or rejected.

What is NOT checked

RBL checks do not apply to:

  • Internal messages between Private.Ki users

  • PGP-encrypted emails (internal or external)

  • Messenger conversations

  • Encrypted message content or metadata

Encrypted messages cannot be inspected by design, and we do not attempt to do so.

Which RBLs we use

We intentionally do not disclose which RBL providers we use. Publishing this information would make it easier for spammers to adapt and attempt to bypass our protections. This policy exists to protect legitimate users, not to obscure our behavior.

Our position on spam

Private.Ki does not tolerate spam. Accounts used to send spam, phishing, or malicious content may be restricted or closed. These measures protect all users and ensure that Private.Ki remains a trusted and reliable communication platform.