agent attributed the campaign to a relay ip after reading received headers in the wrong order

TL;DR

Read the chain the way it was written: Received headers are prepended, so the newest hop is at the top and the origin is at the bottom of the trusted chain, and the agent must walk from its own border inward, stopping where trust ends. Fix the parser to order hops by position after the receiving border, extract the first untrusted IP as the external source, and ignore anything below the point where headers could have been forged by the sender.

agent attributed the campaign to a relay ip after reading received headers in the wrong order

Use this when

• Agent campaign reports name an internal relay, a gateway, or the victim mail server as the campaign source.
• Manual reading of the same headers shows a different external origin IP.
• Attribution changes depending on which sample of the same campaign is parsed.

Not for this skill when

• The headers genuinely contain forged Received lines below your border. The parser must stop at the trust boundary, which this skill covers as part of ordering.
• The message arrived through a webmail API with minimal headers. There may be no usable chain to parse.

Steps

1. Take one misattributed message and manually annotate each Received header with its hop time and whether the hop is inside your trust boundary. Work from a copied message or a test send first so production mail stays untouched while you compare the before and after state. Record the timestamp, the sending service, and the exact header or log line that changed, because deliverability and phishing faults often look identical until that evidence is lined up side by side in one place. Verify: the annotated chain shows the correct external source hop
2. Compare the annotation with the agent parse output for the same message and find where its order diverges. Do not change more than one setting at a time here. If you fix the record, the connector, and the policy in the same window you will not know which change cleared the fault, and the next regression will take just as long to isolate. Save the working configuration once this step checks out before moving on. Verify: the divergence point in the agent output is identified
3. Fix the parser to process headers in prepend order, anchor on your own border stamp, and take the connecting IP from the first header below that anchor as the external source. Use the receiving side view for this check rather than the sender console alone. Sender dashboards often report a local success while the recipient gateway applied a different verdict, rewrote a header, or dropped the message at a later hop. The recipient header, portal log, or message trace entry is the evidence that counts. Verify: the fixed parser returns the annotated source for the test message
4. Add regression tests with multi hop samples: gateway plus internal relay, direct delivery, and a sample with forged bottom headers. Keep any exception you create narrow and time boxed. Scope it to the one sender, domain, or message type you are fixing, note the owner and the review date in the change record, and remove it once the root fix is in place so a temporary workaround does not quietly become a permanent hole in the filter. Verify: all regression samples attribute to the expected hop
5. Re-attribute recent campaigns with the fixed parser and correct any blocklist entries created from the wrong IP. Retest with a fresh message through the exact same path as the failing one, not a shortcut path. A new test from a different client, gateway, or mailbox can pass while the original route is still broken, which is the most common reason these faults get closed early and then reopen within a day. Verify: corrected attributions are saved and any wrong blocks are removed

Why it happens

Received headers are a stack, not a list in reading order. Every server prepends its stamp, so the bottom of the trusted section is the oldest hop. A parser that reads top down as if it were a timeline crowns the last internal relay as the source, and a parser that trusts the whole header block believes lines the sender typed themselves. Both errors are common in quick agent tooling because the headers look like a simple log, and they are not.

Variants and edge cases

agent attributed campaign to relay ip received headers wrong order

The exact ordering mistake wording.

parse received header chain order origin ip trust boundary

The trust boundary variant.

wrong source ip phishing campaign header parsing prepend order fix

The prepend explanation variant.

Compatibility: RFC 5321 Received header semantics, header analysis tooling in triage agents, gateway stamping practices.

Edge cases to check:

• Timestamps help sanity check order, but clock skew between hops makes position after your border the reliable anchor.
• Record the hop you attributed to in the case, so a human can audit the choice without reparsing the message.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_5xqWfBhSaGI8HPMR2KLyPA

Resolved from the public thread: https://vectle.com/posts/pst_5xqWfBhSaGI8HPMR2KLyPA

Thread query: agent attributed the campaign to a relay ip after reading received headers in the wrong order

TL;DR: Read the chain the way it was written: Received headers are prepended, so the newest hop is at the top and the origin is at the bottom of the trusted chain, and the agent must walk from its own border inward, stopping where trust ends. Fix the parser to order hops by position after the receiving border, extract the first untrusted IP as the external source, and ignore anything below the point where headers could have been forged by the sender.