Mailbox health and deliverability
11x treats deliverability as core infrastructure - automatic domain setup, warm-up, health monitoring, rotation of degraded domains, and inbox placement testing.
11x treats deliverability as core infrastructure, not a setting. It configures DKIM, DMARC, and SPF automatically, warms domains automatically, monitors mailbox health in real time, and when a domain's health declines it is pulled from sending and rotated out for a warm replacement. Inbox placement is tested before volume goes out, and blacklisting triggers automatic pausing and cooldown.
The reason this is bundled rather than sold separately: excellent messaging is worth nothing if it lands in spam. Tools that ask you to bring your own mailboxes push this entire discipline onto you.
What's managed automatically
| Capability | Behaviour |
|---|---|
| Domain authentication | DKIM, DMARC, and SPF configured automatically |
| Warm-up | Domains warmed automatically rather than manually ramped |
| Health monitoring | Mailbox health tracked in real time |
| Rotation | A domain whose health dips is pulled from sending and replaced with a warm one |
| Placement testing | Tests whether mail hits primary, promotions, or spam before volume goes out |
| Blacklist detection | Detects flagging, pauses sending, cools down affected mailboxes; recovery starts automatically |
| Capacity | Private sending IPs with capacity tracking, so volume scales cleanly |
Placement testing before volume is the highest-value item here. It converts deliverability from something you discover retrospectively into something you know in advance.
Message construction
Deliverability is also affected by how messages are built. 11x defaults to:
- Plain text, with no tracking pixels or heavy formatting
- Every message unique — no two emails look the same
Identical bulk-looking mail is a spam signal in itself. Per-prospect generation helps deliverability, not just response rates — which is a second reason AI personalization matters.
What you still own
Automation covers infrastructure. These remain yours:
| Yours | Why |
|---|---|
| Choosing a dedicated sending domain | Isolates outbound reputation from corporate mail |
| Verifying DNS independently | Trust but verify — see the tools below |
| Targeting quality | Complaints come from reaching the wrong people, and no infrastructure fixes that |
| Volume discipline | Don't override pacing because early results look good |
Verify with the free 11x tools: domain health · SPF · DKIM · DMARC · blacklist · Google Postmaster
Metrics to watch
| Metric | Want | If it slips |
|---|---|---|
| Inbox placement | Stable or improving, primary folder | Hold volume immediately |
| Bounce rate | Near zero | List quality — stop and fix the data source |
| Complaint rate | Effectively zero | Targeting — tighten the ICP now |
| Per-mailbox variance | Consistent | One bad mailbox drags the whole domain |
| Domains in rotation | Stable | Several rotating at once signals a targeting problem |
Watch per-mailbox figures, not just the domain aggregate. A single mailbox with a high complaint rate can pull down an otherwise healthy domain, and the aggregate hides it.
When automation isn't enough
Rotation and cooldown protect you from the symptoms. They don't fix the cause. If domains are rotating repeatedly:
Stop increasing volume
Adding volume to a reputation problem compounds it.
Check complaint rate first
Complaints mean you're reaching people who aren't remotely in your market.
Tighten the ICP before touching copy
A well-targeted mediocre email beats a brilliant email to the wrong person.
Check where contacts came from
Uploaded lists bounce. Source from the database instead.
Then resume ramping
Gradually, and watch placement daily.