SalesEQ - Inbound emails with incorrect "To" field when forwarded – Incident details

Cloudflare → Cloudflare Sites and Services → Network experiencing degraded performance

Inbound emails with incorrect "To" field when forwarded

Resolved
Degraded performance
Started 3 months agoLasted 1 day

Affected

Resend → General API

Operational from 2:54 PM to 5:47 PM

Resend → Email Sending → Single Email

Operational from 2:54 PM to 5:47 PM

Resend → Email Events

Operational from 2:54 PM to 5:47 PM

Updates
  • Resolved
    UTC
    Resolved

    We have resolved the underlying issue by reverting the unintended breaking change and service has been resumed.

  • Identified
    UTC
    Identified

    A recent change to how Resend processes inbound emails affected customers who receive emails via server-side forwarding rules, where a mail server automatically redirects an email to a different address without rewriting its headers.

    When an email is forwarded this way to a Resend inbound address, the to field in the inbound webhook payload began reflecting the original "To" header (e.g. support@yourcompany.com) rather than the address that actually received the delivery (e.g. your Resend inbound address).

    Direct emails and client-side forwards were not affected.