Google Postmaster Bad Reputation Fix Guide (2026)

Google Postmaster Tools reports domain reputation on a four-level scale: Bad, Low, Medium, High. This rating is Gmail's own internal classification of your sender and it directly drives filter decisions. A Bad rating routes most of your mail to spam within 24-48 hours of the rating dropping.

The four levels translate roughly to:

Bad reputation is Gmail telling you explicitly that something in your sending pattern, volume, list quality, or authentication is broken. The rating is smoothed over ~7 days, so it lags actual behavior. By the time Postmaster shows Bad, the underlying issue has been active for at least a few days.

This guide walks through the exact pause-diagnose-rebuild protocol that reliably moves domains from Bad → Medium → High over 14-28 days. For the general overview of the Postmaster dashboards, see google-postmaster-tools-guide.

"Bad reputation" is not a single diagnostic. It is a symptom that shows up in one place but is caused by signals across five dashboards. Read all of them before deciding on a fix:

The diagnostic pattern you're looking for: which combination of dashboards is unhealthy tells you the root cause.

Do not skip this step. Fixing the wrong root cause (e.g., rewriting content when the actual issue is DMARC misalignment) wastes 1-2 weeks and Gmail's rating moves slowly.

Once you've identified which combination of dashboards is problematic, map it to the specific fix. This table is the single most useful reference in this guide. Screenshot it.

If multiple rows apply, fix them in the table's order. Authentication first, list quality second, content third, volume fourth. Address them in the wrong order and recovery stalls because you're not addressing the strongest signal.

Fixing the root cause alone is not enough. You have to stop sending long enough for Gmail's smoothing window to pick up the corrected behavior. Recovery follows a specific pattern:

1. 1Day 0: Pause all cold campaigns on the affected domain. Keep warmup running. Fix the identified root cause.
2. 2Day 1-3: Monitor Postmaster Tools daily. Ratings usually don't move yet because the rolling window still includes the bad days. This is normal.
3. 3Day 4-7: First signs of improvement if the root cause is fixed. Spam Rate should drop first (within 2-3 days), Domain Reputation starts moving 2-4 days after that.
4. 4Day 7-10: If reputation is improving (Bad → Low, or Low → Medium), resume cold sending at 30% of pre-pause volume. If reputation is still Bad or dropping, the root cause is not fully fixed, so go back to Step 1.
5. 5Day 10-14: Ramp to 60% of pre-pause volume if Postmaster Reputation continues climbing.
6. 6Day 14-21: Back to 100% if Reputation is Medium or better.

Hard rules during the pause protocol:

• Do not touch SPF/DKIM/DMARC during recovery unless that's the identified root cause. Authentication changes during recovery introduce variance and muddy the signal.
• Do not run A/B tests during recovery. Keep template, volume, and sending time constant so you can see what's causing the movement.
• Do not add new mailboxes to the domain during recovery. New mailboxes introduce new warmup load that Gmail has to evaluate.
• Do keep warmup running. Warmup is the positive-signal generator during recovery. Pausing warmup removes the counter-signal and slows recovery.

Warmup is what generates the positive engagement signals Gmail uses to upgrade reputation. But not all warmup is equal:

Pooled warmup (shared across customers): Mailreef, Warmforge, most standalone warmup tools use a pool where your mailbox exchanges mail with every other customer's mailbox. During a reputation recovery, this is risky because if one customer in the pool has Bad reputation, your sends to them get marked as spam, which compounds your problem.

Isolated warmup: each customer's warmup pool is segregated, so your mailbox only exchanges mail with trusted, known-good seed accounts. During recovery, isolated warmup reliably generates positive engagement without cross-customer contamination.

Warmup cadence for reputation recovery:

InboxKit isolated warmup runs at $3/mailbox/mo, specifically engineered for reputation recovery scenarios. Deeper warmup reference in domain-warmup-best-practices.

During the recovery window, three Postmaster metrics matter more than the headline Domain Reputation number because they move faster and predict where Reputation will go next:

The pattern that means "recovery is working":

1. 1Spam Rate drops first (days 2-4).
2. 2Delivery Errors clear (days 2-5).
3. 3Domain Reputation begins climbing (days 5-10).
4. 4Reply rate on live sends recovers (days 7-14).
5. 5Bounce rate normalizes (days 7-14).

The pattern that means "recovery is failing":

1. 1Spam Rate stays above 0.20% despite content changes.
2. 2Authenticated Traffic stays below 99%.
3. 3Domain Reputation stays at Bad or Low after 14 days.

If you see the failing pattern at day 14, the root cause is either misdiagnosed or the domain is structurally damaged. Move to the retire-vs-rehab decision below.

Not every damaged domain is worth saving. Use this decision framework:

The economics: a burner cold email domain costs $10-15 + ~$3/mailbox/mo warmup. Full rehab of a Bad-rated domain takes 21-28 days of reduced sending. Fresh domain + 14-day warmup is typically 2-3x faster than rehab for most cold email setups. This is why professional cold emailers operate with rotating burner domains, and when one gets damaged, they retire it and spin up a replacement without disrupting campaigns. Architecture in how-many-domains-cold-email.

Postmaster Tools has a 5-10 day lag because the ratings are smoothed. That means by the time you see Bad, the damaging behavior has been happening for 5-10 days already. Prevention beats rehab every time.

The three layers of continuous monitoring that prevent Bad reputation:

InboxKit InfraGuard implements all three and auto-pauses sending on a mailbox or domain when any alert fires. The 6-hour check interval means you typically get 24-72 hours of lead time before Postmaster Tools would have shown a problem, enough time to fix the root cause without the reputation drop.

InfraGuard is free for the first month on all plans and then billed per-domain. The Agency plan at $99/mo for 30 slots is a common sweet spot for teams running ~20 cold email domains.

Beyond InfraGuard, two habits prevent Bad reputation entirely:

1. 1Verify every list before sending. 10-minute manual check with NeverBounce or similar prevents the bounce-surge failure mode.
2. 2Keep per-mailbox daily volume under 40/day. The single biggest predictor of a ramp-induced reputation drop is per-mailbox volume above 40/day.

For the full monitoring stack reference, see email-deliverability-monitoring-setup.