Most deliverability anxiety comes from operators who've seen one bad number and don't know whether to panic or ignore it. A reply rate dips from 4% to 3%, a single seed address landed in spam, Postmaster shows Medium instead of High. Is this an emergency? A ticket? A note in the quarterly review? This matrix gives you a decision rule so you stop asking.
Plot the problem on two axes: severity (how much it hurts the business) and trajectory (is it getting worse?). The quadrant tells you the response.
Axis 1: Severity
Severity is the business impact, not the technical interestingness. A DKIM warning on a subdomain you don't send from is zero severity no matter how alarming it looks in a dashboard. A 40% drop in transactional delivery is critical severity even if everything on the reputation dashboard is green.
- Low: single metric mildly off, no revenue impact, no user complaints
- Medium: noticeable metric shift, indirect revenue impact, isolated user complaints
- High: multiple metrics off, direct revenue impact, active user complaints, regulatory exposure
- Critical: emails not reaching users who need them (password resets, order confirmations, payment receipts), major provider block, legal exposure
Axis 2: Trajectory
Trajectory is about the past two weeks. Is the problem getting worse, staying flat, or recovering? A metric stable at a new low for 14 days is a different beast from a metric dropping 5% per day.
- Improving: the number is moving back toward healthy
- Flat: no movement for two weeks
- Slow decline: losing 1–3% per week
- Cliff: losing 5%+ per week or single-event drop over 20%
The four quadrants
Quadrant 1: Low severity + improving/flat — ignore
The metric is mildly off but stable or recovering. Don't spend time on it. File a one-line note in the quarterly review doc and move on. Common examples: one seed mailbox landing in spam on one test, Postmaster reputation ticking from High to Medium on a week with a holiday campaign, complaint rate at 0.05% (half the threshold) holding steady.
Quadrant 2: Low/medium severity + slow decline — monitor
The metric is trending the wrong way but hasn't crossed any important threshold yet. Set up a weekly check, log the number, and give yourself four weeks before acting. Usually the trend stabilises on its own, or you catch it early enough to fix with a cheap intervention (remove inactive subscribers, slow volume growth).
Quadrant 3: Medium/high severity + flat or slow decline — internal fix
Real problem, not yet a fire. This is your internal project territory. Assign an owner, give them two weeks, check in twice. Common examples: DMARC reports showing a vendor sending without DKIM alignment, Microsoft junk folder rate climbing from 5% to 15% over a month, a specific campaign type consistently landing in Promotions.
Before starting the internal fix, run a fresh inbox placement test so you have a before-number to compare against the after-number.
Quadrant 4: High/critical severity or cliff — escalate
Something is actively broken and the trajectory confirms it. This is the quadrant where you wake people up. External escalation means one or more of: a specialist consultant retainer, direct outreach to an ISP postmaster, blocklist delisting process, legal review if there's a DMARC spoofing incident. Common examples: Microsoft blocking all mail with 550 5.7.1, password reset delivery dropping below 80%, Gmail spam rate over 0.3% for three consecutive days, a domain landing on Spamhaus SBL.
Have three things ready: the problem statement in one sentence, the metric timeline (what changed when), and the impact quantified in dollars or users. Escalation without these three is just panic with a bigger audience.
Special cases that jump quadrants
A few scenarios override the matrix because they have second-order consequences the numbers don't yet show:
- Transactional email failing. Password resets, OTPs, receipts. Even 5% failure is critical severity because users lock out of accounts and contact support. Jump straight to Quadrant 4.
- Domain on a major blocklist. Spamhaus, Barracuda, UCEProtect L1. Even if your numbers look fine today, the blocklist will catch up with you. Quadrant 4.
- DMARC spoofing reports. Someone is sending mail as you. Not technically a deliverability problem, but bleeds into one fast. Quadrant 4.
- Regulatory exposure. GDPR, CAN-SPAM, CASL, 152-FZ complaint from a user. Legal, not deliverability — but often surfaces here first. Quadrant 4 with legal in the loop.
Who gets called in each quadrant
Escalation is about who gets pulled away from what they're doing. The matrix should map cleanly to a staffing decision:
- Ignore: nobody — it goes in the doc
- Monitor: the email owner spends 10 minutes a week
- Internal fix: one engineer/marketer, 4–8 hours over 2 weeks
- Escalate: consultant or ISP direct contact, could be a week of multiple people's time
If your instinct is to put everything in Quadrant 4 because "email is important", you'll burn your team out and miss the actual emergencies. If your instinct is always Quadrant 1 because "it's just email", you'll discover the problem when a customer calls support about a missing invoice. The matrix forces honesty.