Cloudflare Access one-time PIN emails blocked by certain email security gateways, including Proofpoint

Summary

Cloudflare Access one-time PIN emails blocked by certain email security gateways, including Proofpoint

This incident has been resolved and the developer documentation has also been updated to reflect the same information: https://developers.cloudflare.com/cloudflare-one/integrations/identity-providers/one-time-pin/#allow-otp-emails-through-your-email-gateway

• Started

  Aug 31, 2026 · 8:16 PM

• Resolved

  Aug 31, 2026 · 10:02 PM

• Duration

  1h 46m

• Severity

  Minor

• ◐

  Investigating

  Aug 31 · 8:16 PM Cloudflare

  Some customers using Proofpoint may experience delayed Cloudflare notifications and login codes. Proofpoint is temporarily deferring messages with an SMTP 421 4.7.0 response. Cloudflare will continue retrying delivery. Affected customers should ask their Proofpoint administrator to allowlist notify.cloudflare.com and Cloudflare IPs 104.30.16.2,104.30.16.3,104.30.16.4,104.30.16.5,104.30.16.6, and 104.30.16.7. If this cannot be configured locally, contact Proofpoint for additional support.

• ◆

  Identified

  Aug 31 · 8:47 PM Cloudflare

  Some customers using Proofpoint may experience delayed Cloudflare notifications and login codes. Proofpoint is temporarily deferring messages with an SMTP 421 4.7.0 response. Cloudflare will continue retrying delivery. Affected customers should ask their Proofpoint administrator to allowlist notify.cloudflare.com and Cloudflare IPs 104.30.16.2,104.30.16.3,104.30.16.4,104.30.16.5,104.30.16.6, and 104.30.16.7. If this cannot be configured locally, contact Proofpoint for additional support.

• ◉

  Monitoring

  Aug 31 · 8:49 PM Cloudflare

  Some customers using Proofpoint may experience delayed Cloudflare notifications and login codes. Proofpoint is temporarily deferring messages with an SMTP 421 4.7.0 response. Cloudflare will continue retrying delivery. Affected customers should ask their Proofpoint administrator to allowlist notify.cloudflare.com and Cloudflare IPs 104.30.16.2,104.30.16.3,104.30.16.4,104.30.16.5,104.30.16.6, and 104.30.16.7. If this cannot be configured locally, contact Proofpoint for additional support.

• ✓

  Resolved

  Aug 31 · 10:02 PM Cloudflare

  This incident has been resolved and the developer documentation has also been updated to reflect the same information: https://developers.cloudflare.com/cloudflare-one/integrations/identity-providers/one-time-pin/#allow-otp-emails-through-your-email-gateway