Cold Emails That Reach the Inbox.

Mailboxes on the provider you choose — Google Workspace, Microsoft 365, on-prem Exchange, Azure Communication Services or Nebuela's own sending servers — provisioned onto domains you own, with every sending DNS record written into your Cloudflare zone and a portal to manage them.

Nebuela is not a sequencer. You keep sending from Instantly, Smartlead or whatever you already pay for; we hand over working credentials and exports.

Google Workspace — the most familiar mailbox on the recipient side and the most conservative choice, provisioned into a Workspace tenant we operate. It is the slowest path to set up, because our Workspace provisioning drives the admin console directly rather than an API.

Microsoft 365 / Exchange — provisioned through the Microsoft Graph API, so it is the more predictable automated path, and typically the cheaper per mailbox.

Custom (our own servers) — mailboxes on Nebuela-managed Postfix and Dovecot with dedicated IPs, per-domain IP binding and per-domain DKIM. The most control and the most isolation; the most dependent on how you send.

If you are unsure, tell us your volume and we will say which one we would put you on — including when the answer is "not us".

Two things sit between payment and a sendable mailbox, and neither is instant. First, orders are reviewed and approved by a person — they do not provision the moment you click submit. Second, DNS has to propagate before mailboxes can be validated, and on the Google Workspace path provisioning drives the admin console rather than an API, which is slower.

Most orders are provisioned and delivered within one business day. Large or mixed-provider orders can take longer; if yours will, we tell you rather than letting it sit.

Yes, automatically during provisioning, through the Cloudflare API. Written per domain: MX, an A (or AAAA) record for the mail host, SPF, DKIM, DMARC, autodiscover on the Microsoft and Azure paths, and the provider's domain-ownership TXT record. Email records left behind by a previous provider are removed first, and SPF is merged into your existing record rather than replacing it.

You do not paste anything by hand. You do need the domain on Cloudflare and an API token scoped Zone:Zone:Read and Zone:DNS:Edit.

The domains are unambiguously yours — you registered them, they are in your registrar account and your Cloudflare account. We never hold them, because we never buy them. Our access is an API token you issued and can revoke at any moment.

The mailboxes are a more nuanced answer, and here is the honest version: on the Google Workspace, Microsoft 365 and Azure paths your domain is added to a provider tenant that Nebuela operates. You get full SMTP and IMAP credentials for every mailbox and can export them whenever you like; you do not get provider super-admin over that tenant.

What happens to those mailboxes if you cancel is not yet documented on this page. It is the question that decides switchers, so we will answer it in writing before you buy rather than leave you to infer it.

Yes. Bring domains you already own — put their DNS on Cloudflare, give us a scoped API token for those zones, and add them to an order. If you would rather not source them yourself, we also register and manage domains for you; ask us for current domain pricing.

Yes. Cloudflare is the only DNS backend we automate. Route 53, registrar-hosted DNS and everything else are not supported — not "not yet supported in your plan", simply not built. Moving a domain to Cloudflare is a nameserver change at your registrar and is free at Cloudflare's entry tier.

Google Workspace is $2.50 per mailbox per month, Microsoft is $1.50 per mailbox per month, and dedicated SMTP infrastructure is $3 per domain per month. Setup is free on all three.

The subscription tracks your live count, and the billing page shows that count next to what is currently on the subscription, so you can see the next invoice before it arrives. Domains are separate: bring your own, or we register and manage them at $12 per domain per year.

There is no setup fee. Billing runs monthly through Stripe and is cancellable from the billing portal — per mailbox on the Google Workspace and Microsoft paths, per domain on dedicated SMTP.

Any minimum mailbox count, minimum term or notice period is confirmed in writing when we quote you — we would rather put it in your inbox than assert "no minimum" on a page before the Terms say so.

No — and we would rather say it plainly than blur it. Nebuela does not operate a warmup engine, a warmup pool or a reply network. The mailboxes are fresh, not pre-warmed.

What we do is carry your warmup settings through to the tool that does run warmup: when accounts are uploaded to Smartlead or pushed into Instantly, warmup enablement, daily warmup volume, ramp-up and reply rate are set per account, so warmup starts the moment the mailbox is connected.

Technically you can create between 1 and 10,000 mailboxes on a single domain, and the default when you place an order is 3. On our own sending infrastructure each domain also carries its own daily send ceiling, set per domain.

The 1–10,000 range is a technical limit, not a recommendation. Tell us your volume and we will tell you how we would split it across domains.

Instantly — two ways: a formatted CSV export, or a direct push that connects accounts into your Instantly workspace in batches with live progress and retry. The direct push signs into your Instantly workspace and connects the accounts for you, so it needs your Instantly login.

Smartlead — a real API upload, with per-account daily limit, warmup enablement, warmup volume, ramp-up and reply-rate settings applied as the accounts land.

EmailBison — CSV export in their format.

Anything else — generic CSV plus full SMTP and IMAP credentials for every mailbox, which is all any sending tool needs. We are not going to list a tool as an "integration" when it is really a spreadsheet.

A sweep runs every 15 minutes across your domains. It detects missing DKIM records, MX/SPF/DMARC/autodiscover that are no longer configured, missing mailbox credentials, SMTP or IMAP authentication failures, DKIM mismatches and degraded sending servers — and repairs what it can, then re-checks its own work.

Sending IPs on our own infrastructure are checked against Spamhaus, Barracuda and SpamCop on every sweep; a listed IP is flagged and taken out of rotation. Inbox placement and spam-score testing are available as a service on top of this — ask us for the current scope.

What we do about a mailbox the provider suspends, or a domain that gets burned, is handled case by case today and is not yet a published policy — ask us what it would mean for your setup.

Yes. Generate additional mailboxes on an existing domain at any time, or add new domains to a new order. The Stripe subscription quantity follows your live mailbox count, and the billing page shows that live count next to what is currently on the subscription, so you can see the effect before the invoice arrives.

Yes, as a managed service — ask us and we run it for you, then send the result. We test where your campaign actually lands (inbox, a tab, or spam) broken down by provider, and flag the copy that hurts placement.

To be precise about what is and is not self-serve: the portal shows you authentication checks, per-mailbox SMTP/IMAP validation and the 15-minute repair sweep. Placement testing is not a button in the portal today — it is something we run on request.

Worth saying plainly: we don't print a headline placement percentage on this page. Placement depends heavily on your list, your copy and your sending behaviour, so a number measured without those is decoration — run the test on your own campaign and read your own result.

Subscriptions are managed through the Stripe billing portal, where you can update payment details and cancel.

The refund window and notice period are not published on this page yet. Ask before you buy and we will send them in writing.

Email info@nebuela.com. The contact form below reaches the same inbox.

We have not published support hours or a response-time commitment, so please do not read one into the page. Both channels above are monitored by a person.