Buy & Warm Sending Domains

GTM Engine can send your campaign email natively, using dedicated sending domains and mailboxes. Mailbox warmup is for cold outbound; domain warmup is a separate marketing-domain option for newsletters, release notes, and other broadcast-style sends. Keeping cold outreach on separate domains protects the reputation of your primary domain.

This guide walks through buying or connecting a sending domain, creating mailboxes on it, and choosing the right warmup flow.

How It Works

1. You buy a fresh domain (paid with credits, at cost) or connect a domain you already own via DNS.
2. GTM Engine provisions the domain in its sending infrastructure and sets up the required DNS records.
3. You create one or more mailboxes on the domain (e.g. outreach@yourdomain.com).
4. For cold outbound, you turn on mailbox warmup for each mailbox (billed monthly per mailbox in credits) to build and maintain sender reputation before it sends real campaign email.
5. For marketing-style domains, you can separately start domain warmup after acknowledging that it does not warm the visible outbound mailboxes.
6. Once fully warmed and live, the mailbox sends campaign email, and GTM Engine tracks deliveries, opens, clicks, replies, and bounces.

Where to Find It

Campaign Admins can open Campaign Engine → Domains and Mailboxes to manage sending domains, mailboxes, warmup, and health checks.

Buying a Domain

Domains are paid for with your organization's credits, charged at cost (100 credits = $1.00).

1. On the Domains tab, click Buy a domain.
2. Either type one or more candidate domains and click Check, or click Suggest to have GTM Engine propose five distinctive, business-like secondary domains based on your brand.
3. GTM Engine checks each suggestion for availability before showing the price. Unavailable suggestions are replaced automatically, and you can dismiss names or generate more.
4. Click Buy on the domain you want.

After purchase, GTM Engine automatically registers the domain in its sending infrastructure, configures DNS, and begins provisioning. If registration ever fails, your credits are automatically refunded.

Connecting a Domain You Already Own

If you'd rather use a domain you already control:

1. On the Domains tab, click Add existing domain.
2. Enter the domain (for example, mail.acme.com).
3. GTM Engine registers it and the domain lands in Provisioning. Expand the domain row (the chevron / "Show DNS records") to see the DNS records you need to publish — each row lists the record type, host/name, value, and current verification status, with a copy button on each value. The DNS panel refreshes records from the sending provider when it opens so stale setup instructions recover automatically.
4. Add those records at your DNS provider, then click Verify on the domain row.

The domain becomes active once the records propagate and verification succeeds. DNS changes can take up to 48 hours to propagate; while a domain is still provisioning the list auto-refreshes so its status updates without a reload, and you can re-run Verify at any time.

Deleting Domains and Mailboxes

You can remove sending infrastructure you no longer need on Campaign Engine → Sending:

• Delete a mailbox — the trash action on an inbox row removes the mailbox from GTM Engine and Mission Inbox after a quick confirmation.
• Delete a domain — the trash action on a domain row opens a confirmation that asks you to type the exact domain name. Deleting a domain cascades: it removes every sending inbox on the domain, cleans up the provider-connected DNS records, and deletes the domain itself. For a domain you own, also remove any records you added at your own DNS provider — GTM Engine can only clean records on connected providers.

Both actions are permanent and cannot be undone.

Creating Mailboxes

Once a domain is active, you can add mailboxes to it:

1. Choose the domain and add a mailbox with a local-part (the part before the @), a sender name, and a daily send limit. New mailboxes default to 30 emails/day, which is the recommended cold-outbound ceiling.
2. Optionally check Start mailbox warmup for cold outbound while creating the mailbox, or turn on mailbox warming later before you start sending.

For deliverability, GTM Engine recommends about 30 outbound emails/day/mailbox and no more than 3 live outbound mailboxes per domain.

Mailbox Warmup for Cold Outbound

Mailbox warmup builds and maintains a mailbox's sending reputation by exchanging email with a trusted network. This keeps cold-outbound campaigns landing in the inbox instead of the spam folder. Plan on 2–4 weeks of warming before sending real volume.

Warmup is an always-on deliverability service, not a one-time two-week task. The first 2–4 weeks are a hard waiting period for real campaign sends: a warming mailbox does not send live GTM Sending campaign email until it is fully warmed. After that, keep warmup enabled so the mailbox continues reputation maintenance while it sends.

You control mailbox warming from Campaign Engine → Sending:

• Warm on creation — check Start mailbox warmup for cold outbound when adding one mailbox or bulk-adding mailboxes across domains.
• Warm a single mailbox — expand a domain and click Warm on any mailbox that is not already warming or warmed.
• Warm mailboxes in bulk — use Bulk Warm Mailboxes or the warming control on a domain row to start warmup for all eligible mailboxes in the selected scope. Already warming or warmed mailboxes are skipped.

Mailbox warmup is billed at 350 credits per mailbox per month while warmup is enabled. Turning warming on charges a prorated first month based on the remaining days in the current UTC calendar month; the next calendar month and each month after that are charged at the full monthly rate. Disabling warmup stops future monthly charges but does not refund the current month. The per-mailbox monthly rate is shown in the confirmation before you enable it. Before starting, GTM Engine asks you to acknowledge that mailbox warmup is for cold outbound, should remain on after the initial warmup period, and does not start domain warmup.

Domain Warmup for Marketing Domains

Domain warmup is separate from mailbox warmup. Use it for marketing domains you plan to use for newsletters, release notes, lifecycle emails, and other broadcast-style sends. It calls the provider's domain-level warmup flow and does not warm the visible outbound mailboxes on that domain.

On Campaign Engine → Sending, active domain rows include a Domain warmup action. Before starting, GTM Engine explains the difference and asks you to acknowledge that domain warmup is domain-only and not a substitute for mailbox warmup. Domain warmup is billed at 2,000 credits per domain per month while enabled, with the activation month prorated.

Capacity, Domain Purpose, and Pool State

Campaign Engine → Sending includes a capacity summary that compares:

• total capacity/day from fully warmed live outbound mailboxes
• safe capacity/day after subtracting unhealthy mailboxes recommended for decommission, including future step-ups when warming mailboxes complete
• upcoming capacity from mailboxes that are still warming
• warmed reserve capacity in the warming pool
• scheduled sends/day over the next 7 days
• actual sends/day over the past 14 days
• utilization and recommendations for adding mailboxes or domains

Only fully warmed, live mailboxes on outbound domains count toward current cold-outbound capacity. Marketing-domain mailboxes, warming mailboxes, warming-pool mailboxes, and deactivated mailboxes count as 0 current cold-outbound capacity.

Domains can be tagged:

• Outbound — dedicated cold-outbound sending domains.
• Marketing — newsletters, release notes, lifecycle, and broadcast-style sends.

Domains and mailboxes also have pool states:

• Live — eligible for campaign sending.
• Warming pool — backup/reserve capacity that can be warmed and health-checked but is not used for live campaign sending.
• Deactivated — removed from sending rotation without deleting historical data.

Health checks can flag poor or spam-heavy mailboxes as Recommend deactivating.

Checking Mailbox Health

From Campaign Engine → Sending, run an inbox-placement check for one mailbox, selected domains, or all eligible mailboxes. Health checks cost 50 credits per mailbox per run. While the check runs, the page updates its progress every few seconds and stops automatically when the provider completes or fails.

Campaign Admins, Admins, and RevOps users can also turn on Weekly health checks for the organization. When enabled, GTM Engine automatically checks active GTM Sending mailboxes that have never been checked or whose last completed check is more than 7 days old. These scheduled checks use the same 50-credit per mailbox price as manual checks. If Auto-disable poor health is also enabled, any active mailbox with a completed score below 50 is disabled automatically.

Completed checks show the exact percentage of test messages that reached the inbox:

• Excellent: 90–100%
• Good: 70–89%
• Fair: 50–69%
• Poor: 0–49%

Open the health result to review inbox, promotions, and spam placement; SPF, DKIM, and DMARC authentication; recommended next steps; and the last-check time. Old results are marked Stale, mailboxes without a result are Not checked, and failed checks can be retried.

Domains do not receive a separate provider score. The domain row shows the lowest current mailbox result so one strong mailbox cannot hide another mailbox that needs attention.

Replies, Bounces, Unsubscribes, and Analytics

When you send natively, GTM Engine watches for replies, bounces, and unsubscribes:

• A reply, hard bounce, or unsubscribe automatically removes that contact from the campaign and skips its remaining steps, so you never email someone who already replied or opted out. (Replies complete the sequence; bounces and unsubscribes end it.)
• Hard-bounced addresses are suppressed so you don't keep emailing them.
• The Enrollments tab shows why each contact is out of sending, and the campaign Analytics tab shows delivered, opened, clicked, replied, bounced, and unsubscribed counts and rates, plus an "Out of sending — by reason" breakdown.

Unsubscribe Links for Marketing Email

Marketing email needs a clear way for recipients to opt out. Each campaign has an Include unsubscribe link toggle (turned on by default for marketing-type campaigns like newsletters and lifecycle sends):

• When on, every email includes a one-click unsubscribe link. Place it yourself in your content with the {{ system.unsubscribe_url }} variable, or let GTM Engine add a small footer link automatically.
• Clicking the link removes that contact from the campaign immediately — no login required.

Doing It with Genie

You can ask Genie to handle most of this conversationally — for example, "suggest five sending domains", "is acmeworks.com available?", "buy acmeworks.com", "connect mail.acme.com", "create an outreach mailbox on that domain", or "is my new domain warmed up yet?". Genie confirms the domain and its credit cost before purchasing.