Almost every team has one: a forwarding rule quietly holding a workflow together. Mail to one address bounces to another, a shared inbox copies a Slack channel, a personal account relays to a tool. It works right up until it does not — and because forwarding is invisible, no one notices for days.
Why it breaks
- Rate limits. Providers cap auto-forwarding. Cross the threshold and messages are silently delayed or dropped.
- Stripped attachments. Forwarding can mangle or remove attachments, so the most important payload never arrives.
- Broken authentication. Forwarded mail often fails SPF and DMARC at the next hop, landing in spam.
- Single points of failure. One person's mailbox change, vacation auto-reply, or full quota takes the whole chain down.
The defining feature of a broken forwarding rule is silence. Nothing errors — messages simply stop arriving.
What to do instead
The fix is not a better forwarding rule — it is making the routing observable. Instead of a message vanishing into a forward, it enters a system where every hop is recorded.
- Explicit rules you can read, version, and test.
- Delivery logs that show exactly what was forwarded and whether it landed.
- Retry and replay when a downstream system was briefly unavailable.
The takeaway
Forwarding fails quietly because it was never meant to carry a workflow. Move the routing into infrastructure you can see, and "did that email ever arrive?" stops being a question you cannot answer.