# Fix email authentication for kayak.com

You are working on the DNS and mail configuration for kayak.com.
Measured by MailAuthWatch on 17 Oct 2026 from public DNS. Grade A (100/100).
Report: https://www.mailauthwatch.com/check/kayak.com

## What is published right now (do not assume anything else)
- SPF (TXT kayak.com): v=spf1 include:_spf.psm.knowbe4.com include:mail.zendesk.com include:_spf.presscloud.com include:helpscoutemail.com include:kayak.com._nspf.vali.email include:%{i}._ip.%{h}._ehlo.%{d}._spf.vali.email ~all   — valid, 6 of 10 lookups
- DMARC (TXT _dmarc.kayak.com): v=DMARC1; p=reject; pct=100; adkim=r; aspf=r; rua=mailto:dmarc_agg@vali.email
- DKIM: google._domainkey (1024-bit), k1._domainkey (1024-bit), k2._domainkey (2048-bit), k3._domainkey (2048-bit), s1._domainkey (2048-bit), s2._domainkey (1024-bit), mandrill._domainkey (1024-bit), zendesk1._domainkey (2048-bit), zendesk2._domainkey (2048-bit), dk._domainkey (1024-bit)
- MX: mxa-009e5101.gslb.pphosted.com, mxb-009e5101.gslb.pphosted.com  → Proofpoint
- Nameservers: blue.foundationdns.com, blue.foundationdns.net …  → DNS host not recognised

## Tasks, in order of impact
### 1. 5 DKIM keys are 1024-bit.
Why: Selectors google._domainkey, k1._domainkey, s2._domainkey, mandrill._domainkey, dk._domainkey are under 2048 bits, which some receivers already downgrade. 
Rotate to a 2048-bit key at the sending service.

## Rules
- Publish exactly one SPF record; never add a second v=spf1 TXT.
- Do not remove any include: or ip4: you cannot account for; mail may depend on it.
- Do not set DMARC to p=reject in one step; stage through p=none → quarantine → reject.
- Show the planned DNS changes as a diff (record, old value, new value) before applying them.
- If you cannot access the DNS provider or Proofpoint, stop and say exactly what access you need.

## Verify
  dig +short TXT kayak.com
  dig +short TXT _dmarc.kayak.com
Then open https://www.mailauthwatch.com/check/kayak.com?fresh=1 and confirm:
  the grade is unchanged and no new issues appear. Target grade: A.

## Report back
List each record you changed (name, type, old value, new value), what you verified, and anything you could not do.