Product overview

The cold-email workflow, built to switch and automate.

MailSequence brings business inboxes, DNS setup, warmup, verification, sequences, rotation, replies, and automation into one focused platform for agencies and lean outbound teams.

Follow the complete setup-to-reply workflow →

Bring or buy business inboxes·API on every plan·Staged migration support

Complete workflow

From sending infrastructure to qualified replies.

Keep the data and CRM tools your team already uses. MailSequence handles campaign sending, replies, and the controls around them.

Connect or buy inboxes

Authorize Google Workspace or Microsoft 365 synchronization and verify SMTP sending readiness, or purchase configured business inboxes in-product.

Authenticate domains

Use the Cloudflare-based setup path for nameserver delegation and authentication records, then verify the resulting DNS before sending.

Transfer or build

Check Smartlead or Instantly source compatibility before transferring supported records, or create a sequence from scratch.

Verify and enroll

Verify contacts before sending, preserve suppression decisions, and enroll the right audience.

Warm and rotate

Ramp inboxes progressively and distribute sending through campaign pools with conservative limits.

Handle replies

Work from a unified inbox, stop follow-ups on reply, and monitor replies, bounces, and health.

Why MailSequence

Four reasons to switch.

Migration

Switch one campaign at a time

Use your authorized Smartlead or Instantly API key for a compatibility check, then transfer supported records and reconnect senders before launch.

Explore migration →

Agencies

A workspace for every client

Keep client data isolated, manage organization-level connections, apply role-based access, and automate onboarding through the provisioning API.

Explore team workspaces →

Developer platform

A real API on every plan

Use a versioned REST API, public OpenAPI documentation, scoped keys, idempotent writes, signed webhooks, and hosted MCP.

Explore the developer platform →

Deliverability

Practical sending safeguards

Combine authenticated business inboxes, domain setup, verification, warmup, rotation, suppression, and conservative limits. Placement still depends on mailbox providers and recipient response.

Review deliverability controls →

Capability map

What the product covers.

Operating jobMailSequence capabilityBoundary
Mailbox setupOAuth synchronization plus SMTP readiness, or included provisioned inboxesAdditional inboxes cost extra
Domain authenticationCloudflare-based SPF, DKIM, and DMARC setup pathVerify the resulting records before sending
Audience preparationCSV/API import, verification, lists, suppressionConnect your chosen prospect data source
Campaign operationSequences, schedules, pools, limits, stop-on-replyNo LinkedIn or dialer workflow
Reply operationUnified threads, tagging, assignment, response draftsNot a full sales CRM
AutomationREST API, webhooks, MCP, provisioningPlan and rate limits apply
MeasurementSends, replies, bounces, unsubscribes, healthNo open-rate claims

Connect MailSequence to your existing sales stack. Keep Apollo, Clay, or your CRM where they fit. Use supported connections and the public API for automation.

FAQ

Frequently asked questions

How does MailSequence fit into an existing sales stack?

MailSequence handles business email campaigns, sender controls, and reply management. It connects with customer-owned data and CRM tools, so teams can keep their preferred prospecting and sales systems around it.

Can I provision inboxes inside MailSequence?

Yes. Every plan includes a defined provisioned-inbox allowance with no markup on that allowance at launch. You can also authorize synchronization for supported inboxes you already own. Additional provisioned inboxes cost extra.

What can I transfer from Smartlead or Instantly?

Start with a read-only compatibility check using your authorized source API key. The exact campaign, sequence, lead, account-metadata, and block-list records available must be confirmed against the current source API before transfer.

Is the developer platform available on Starter?

Yes. The public REST API, signed webhooks, and hosted MCP server are available on every plan. Plan capacity and rate limits still apply.

Does MailSequence guarantee inbox placement?

No. MailSequence supports authentication setup and provides verification, warmup, rotation, suppression, limits, and health controls. Domain history, list quality, copy, volume, and recipient behavior still affect delivery.

Run the cold-email workflow in one focused platform.

Choose a plan, connect or purchase business inboxes, and build or assess your first campaign.