Seeing a mailbox flagged as "burned," a domain on a blacklist, or a scary spam score can be alarming — but a flag is not a verdict, and the same word can mean very different things. There are three separate situations, each with its own answer. The first step is always to work out which one you're looking at.
Situation 1: Smartlead or Instantly shows a "burned" status
Tools like Smartlead and Instantly run their own warmup pools, and a "burned" label usually reflects that tool's pool — not the reputation of your Maildoso domains or mailboxes.
If your mailboxes are active and configured correctly on Maildoso, a "burned" flag in the sequencer is not a sign of a real reputation problem.
What to do: keep warmup running normally. Don't pause campaigns, reduce volume or replace domains based on this label alone. Check the reputation your dashboard reports instead — see Understanding your mailbox reputation scores.
Situation 2: A blacklist checker flags your domains (SURBL, Spamhaus DBL) or IPs
Domain blocklists like SURBL and Spamhaus DBL, and IP blocklists that catch one of our rotating sending IPs, are the most common source of scary-looking reports — and none of them mean your domain's reputation is damaged.
SURBL (and similar URL lists like SpamRATS): no measurable impact on inbox placement. See SURBL Listings and Deliverability Impact.
Spamhaus DBL: also no impact on Google or Microsoft placement — we regularly run spam tests on DBL-listed domains and see them inbox normally. Google stopped using Spamhaus DBL as a spam signal in August 2026 and dropped SURBL the year before. Spamhaus lists batches of lookalike or branded domains bought together — a naming pattern, not a reputation problem. Full guidance: What about Spamhaus DBL?
A flagged sending IP (Spamhaus CSS/SBL/XBL, Barracuda and similar): we rotate sending IPs automatically and listed IPs are rotated out. See Sending IPs: rotation and blacklisted IPs.
"A checker says my DKIM is missing": normal — our DKIM uses our own selector, and tools that only look for a default selector miss it. See A checker or audit tool flags SPF, DKIM, DMARC or PTR.
What to do: keep sending and warming up as usual; a listed domain that's still new should simply finish its standard warmup. There's nothing to fix, no delisting to file, and no need to replace domains — a listing never qualifies for a free replacement, credit or refund (see Domain replacement).
Situation 3: Google rejects your emails, a placement test shows 0% inbox, or you measure a real spam rate
This one is different. A genuine rejection from Google, a placement test that consistently shows almost no inbox placement, or a spam rate measured across your own campaigns points to a real issue — and even here there are fixes, from warmup recovery to content optimization.
Don't ignore it or assume it's a false positive. The fastest route is a free Deliverability audit with our expert: log in, click Deliverability audit in the top bar of your dashboard, and pick a time. You can also contact us so our deliverability specialists can review your case.
Also review your outreach practices: enough spintax variation, an unsubscribe option, and clean, well-targeted prospect lists. Monitor bounce rates and SMTP responses in your sequencer.
Send us the details first — even if you're thinking about cancelling
In the large majority of cases we can help, but we can't tell which situation you're in without the specifics:
the email address on your account and the affected domains or mailboxes;
which blacklist or tool flagged them (SURBL, Spamhaus, MXToolbox, Hetrix, a sequencer warning, an audit report — a screenshot helps a lot);
whether you're seeing actual bounces, rejections or spam placement — if so, the full headers of one rejected email or your placement-test result;
your current warmup settings and how long the mailboxes have been warming (warmup volume that's too low or too recent is the most common real cause we find).
Very often the "blacklisting" turns out to have no real impact, or it's fixable within days — and you keep your domains, your warmup progress and your campaigns.
Your dashboard's own reputation view
On the Email accounts page, and in each mailbox's details panel, you'll see a Google Score and a Microsoft Score with the date they were last checked. A brand-new mailbox can read low during its first couple of weeks of warmup — let it finish warming up before reading anything into the score.
Mailbox rotation is designed so that individual mailboxes take the hit instead of your main domain. If a mailbox does get burned, the recovery is simple — stop sending prospecting emails from it but keep warming it up. It usually recovers in about 2–4 weeks; replacing domains is rarely necessary.
How to recover burned mailboxes
Stop all cold outreach from the affected mailboxes — campaigns and follow-ups — to prevent further damage.
Keep warmup running. Maildoso SMTP mailboxes: 80 emails/day per mailbox, 45% reply rate, no daily increment, for 1–2 weeks (up to 3 for severe cases). Google Workspace mailboxes: 25 emails/day, 30% reply rate, increment 2–3 emails/day, for 1–2 weeks. Afterwards, reintroduce sending gradually at low volumes.
Evaluate progress. Week 1 is too early to judge; in week 2 look for slight improvements in placement; if placement is still poor in week 3, consider the mailbox permanently burned.
A permanently burned mailbox can be replaced without extra charges: delete it and create a new one in the same slot, then warm the new mailbox up before resuming campaigns.
What we don't do: delisting requests
We don't file SURBL or Spamhaus delisting requests on your behalf, and we don't recommend spending time on them — the listing has no delivery effect. Spamhaus treats any cold outreach as spam by policy and generally won't delist a domain used for it. To reduce how often your domains get listed, choose unique, generic domain names rather than a batch of lookalikes of your brand — see Buying new domains: how to keep them off Spamhaus and SURBL.
Where refunds fit in
A refund is the last resort, not the starting point. It only comes into the conversation after we've reviewed your situation and genuinely couldn't help — and eligibility then follows our standard policy (the 30-day new-customer guarantee and its exclusions), described in Refunds and cancellations. A blacklist flag by itself — SURBL or Spamhaus DBL — is not a reason to refund, replace or abandon your setup.
Do you guarantee inbox placement?
No — inbox placement depends on factors like sending volume, list quality and message content. Maildoso provides IP rotation, reputation scoring and warmup support to help you get the best deliverability.