Deliverability
Email deliverability: what Dooxout controls and what it does not promise
Email deliverability is whether your messages reach the recipient instead of the spam folder or a bounce, and it depends on authentication, sender reputation, list quality, sending pace and content. Dooxout controls its side of that: suppression that cannot be switched off, unsubscribe headers, provider-aware pacing, reactions to bounces and complaints, and a preflight check. It does not promise inbox placement.
What drives email deliverability
Six factors do most of the work. The table shows what each one means and what Dooxout does about it.
| Factor | Why it matters | What Dooxout does |
|---|---|---|
| Authentication | SPF, DKIM and DMARC show that the message really comes from your domain. | Checks the records before the first send and again in preflight. |
| List quality | Invalid addresses bounce, and unwanted mail draws complaints. | Verifies addresses, shows valid, risky, invalid and unknown counts, and scrubs the audience against suppressions. |
| Sender reputation | Domains and mailboxes build a history that receivers remember. | Separate sending domains, low starting caps that rise with mailbox age and per-mailbox metrics. |
| Pace and provider | Each receiving provider tolerates a different speed. | Looks up the recipient mail provider, groups sends by provider and throttles per provider, with a cooldown when a provider pushes back. |
| Opt-out handling | Hard-to-find unsubscribe links cause complaints. | Puts an unsubscribe link and the List-Unsubscribe headers on every message, and suppresses anyone who unsubscribes or complains. |
| Content | What you write and link to affects how a message is judged. | Shows the rendered message in preflight and tests it before the launch. |
What Dooxout does for deliverability
Suppression that cannot be switched off
An address that unsubscribes or complains is suppressed in that workspace across every channel, and no setting, agent or override changes that. Only the recipient, by subscribing again, or a workspace admin with a reason on record can lift it.
List-Unsubscribe and one-click opt-out
Every message carries an unsubscribe link and the List-Unsubscribe headers, including the one-click form. Replies such as "stop" or "remove me" take the same suppression path. The details are in One-click unsubscribe and the List-Unsubscribe header.
Provider-aware limits and cooldown
Dooxout resolves the mail provider of each recipient and sends through a queue per provider. Each provider has a state: normal, hot, throttled or frozen. When a provider pushes back, pace slows, and a frozen provider gets a cooldown before sends resume.
Bounce and complaint reactions
A hard bounce suppresses the address and ends its sequence. A complaint suppresses it and counts as a strong negative signal. When bounces or complaints pass the thresholds in your policy, sending pauses automatically, and the thresholds are yours to edit.
Preflight before launch, through DeliverProbe
Before a campaign starts, Dooxout sends the first message, rendered with real fields, from each sending mailbox through the same path as the live send to DeliverProbe. The service analyzes headers, SPF, DKIM, DMARC, content and blocklists, and returns a score and findings. Where seed mailboxes are enabled, it can also report where the test message landed. That is a measurement of one test message, not a forecast.
- A low score, a high spam share among seeds or a failing authentication check blocks the launch.
- If DeliverProbe cannot be reached, the result is "could not check", and a person must confirm with a reason. It is never skipped silently.
- A result goes stale when the template, mailbox or DNS changes.
- A person with the override right can launch against the report after a warning, logged in the audit log. An agent cannot.
Message content and headers go to the DeliverProbe service for analysis. For infrastructure, see cold email infrastructure.
What Dooxout does not promise
Mailbox providers decide where a message lands, so Dooxout publishes no inbox placement percentages and assures no delivery result. Limits are conservative defaults, not a guarantee. Open counts are shown as approximate, because Apple Mail Privacy Protection inflates them, and A/B decisions use replies instead of opens.
The platform warns and recommends, and you decide. If you send a cold list from your own mailboxes or your own Amazon SES, SparkPost or Elastic Email account, it shows the risks, and you confirm responsibility once. For the cold lists themselves, you need a legal basis to contact the people on them.
Email deliverability tools, monitoring and audit in one place
If you are comparing email deliverability tools or services, note what this is: a platform you operate, with controls on the sending side. Preflight acts as the audit before a launch. Monitoring means delivery events you can tail through the API or MCP, per-mailbox metrics and automatic pauses. An optional recheck can run on active mailboxes.
A launch checklist
- SPF, DKIM and DMARC pass for every sending domain.
- Every sending mailbox is verified and starts on a low cap.
- The list was verified, and the risky and invalid shares are acceptable to you.
- Unsubscribed and complaining addresses are suppressed, which is always on.
- The unsubscribe link and the List-Unsubscribe headers are present.
- Preflight and the DeliverProbe test passed, or you read the findings and decided.
- Bounce and complaint thresholds for auto-pause are set where you want them.
- You have a legal basis to contact the people on the list.
Read next
- Cold email deliverability: what actually moves it
- SPF, DKIM and DMARC for cold email
- One-click unsubscribe and the List-Unsubscribe header
- Cold email without warm-up
- Cold email infrastructure: domains, mailboxes and DNS
- Safe AI agent access to outbound sales
More on the platform: pricing, the MCP quickstart, agency workspaces, integrations, AI outbound sales, white label cold email, the blog and the home page.
Deliverability questions
What is email deliverability?
It is how often your messages reach the recipient and where they land: the inbox, the spam folder or a bounce. It depends on authentication, sender reputation, list quality, sending pace and content.
Does Dooxout promise inbox placement?
No. Mailbox providers decide where a message lands, and nobody outside them controls that. Dooxout controls its own side: suppression, unsubscribe headers, pacing, reactions to bounces and complaints, and a preflight check. It publishes no inbox placement percentage.
What does the preflight check test?
Preflight checks DNS, the sender identity, the audience and its verification status, then sends a test message from each sending mailbox to the DeliverProbe service for an analysis of headers, authentication, content and blocklists. See cold email infrastructure.
Can I switch off suppression or the unsubscribe link?
Suppression of addresses that unsubscribed or complained cannot be switched off, by you or by an agent. Other protections are on by default, and changing them needs a warning and a logged confirmation. See security.
What happens when a mailbox gets bounces or complaints?
A hard bounce suppresses the address, and a complaint suppresses it and stops its sequence. A soft bounce may be retried on the same step up to two times. When bounces or complaints pass your thresholds, sending pauses automatically.
See the preflight check on your own setup
Request a demo and bring a sending domain. We reply within one business day.