Does Cloudflare block ProtonMail?

While dealing with the headache of ticket #2336045, I’ve tried to respond (via email) by replying to a couple emails and it seems as though my email specifically, or more likely, my email provider seems to be blocked by the [email protected] email I am being told to reach out to. It seems that every time I try send a message I receive an email from: “[email protected]” with the subject: “Delivery Status Notification (Failure)”, with it saying (among the technical gibberish):

“Your email to group [email protected] was rejected due to spam classification.
The owner of the group can choose to enable message moderation instead of bouncing these emails.
More information can be found here: Messages from a bulk sender bounce - Google Workspace Admin Help”.

How do I deal with an issue if I’m supposed to email support and the message will not go through?

I get the same thing here when sending from a address, I’ll pass this report along.


I have at least five email messages successfully sent to @cloudflare email address this month from my @protonmail address. The most recent was on December 22.

Does the bounced mail happen to show your original messages full headers with a spam score?

Only from Protonmail itself, I think:

X-Spam-Status: No, score=-1.2 required=10.0 tests=ALL_TRUSTED,DKIM_SIGNED,
shortcircuit=no autolearn=disabled version=3.4.4
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on

Otherwise I don’t see any obvious clues in the headers.


So far I have not noticed anything particular about the message that has not already been stated, however the issue seems to persist since this has first since posted.

This topic was automatically closed 15 days after the last reply. New replies are no longer allowed.