Inboxes for Grok

The case for Grok in outreach is the research. It reads X, so the first line of an email can be about what a founder said on Tuesday rather than what their website said in 2024, and an agent that does that for every account on a list, then sends from a mailbox you connected, produces outreach no template approaches. Grok connects to Google Workspace and Microsoft 365 accounts to read, draft, schedule and send, and our mailboxes are exactly those accounts, with you as admin.

Nothing of ours talks to Grok, and this page does not pretend otherwise. We sell the mailboxes: separate domains built for cold email, authenticated, with sender history, with you as admin. You connect them to Grok the way you would connect any Workspace or 365 account, and the page is about doing that and keeping the agent to a pace a mailbox survives. We are not a partner of xAI and this is not a review of Grok.

• Separate domains, never the company one. A researched email that bounces is filed against the domain like any other. Our prewarmed orders come with the domain included, forwarded to your site, authenticated before handover.
• Allow the connection as admin. Google Workspace and Microsoft 365 both let an admin control which outside apps an account may authorise, and you are the admin of every mailbox we deliver. If a connection is refused, that setting is where to look.
• Authentication confirmed. SPF, DKIM, DMARC and forwarding are configured before you log in. The authentication checker confirms it for one domain; the same check is an endpoint the agent can call for every domain in the fleet.
• Addresses verified. Grok can research a person whose address no longer exists, and a bounce is the loudest signal a new mailbox sends. The waterfall calculator finds the cheapest verifier order for a list.
• Two-factor decided. Disable 2FA on the receiving account before delivery day, or keep it on and grant restricted sub-account access to our support address. Orders where neither has happened take longer than 48 to 72 hours.

Written as what you are doing rather than as a click path, because Grok’s settings move and a page full of yesterday’s button labels makes everything around it look stale.

1. 1Size the fleet and order it. One researched email to each of 150 people a day is about 10 Google mailboxes at the paces below. The calculator gives the number; order in the portal, and the mailboxes arrive within 48 to 72 hours of payment with you as admin.
2. 2Connect each mailbox through Grok’s Google Workspace or Microsoft 365 connection. Sign in as the mailbox, authorise, repeat per mailbox. Azure tenants are Microsoft 365 mailboxes and connect the same way. The credentials come to you at delivery, not through any API of ours.
3. 3Give Grok the cap as a standing instruction. The figures below, per mailbox per day, spread across the working day rather than in a burst at nine, rotating across the connected mailboxes so no mailbox carries more than its share.
4. 4Schedule the runs, reading first. A daily run: check the connected mailboxes for replies, out-of-office and unsubscribes, suppress, research the next accounts, write, send within the cap, stop. The bounce analyzer tells a bad address from a blocked domain when bounces arrive.
5. 5One display name and signature across the fleet. A first cold email with no display name and a bare signature is advertising exactly that. One line of signature, no links in it, and no tracking pixel from a shared domain.

One-to-one outreach is lower volume than a sequence, which is the good news; the bad news is that an agent with no cap can do a week of volume in a minute. Size the fleet for the daily number with the calculator, and let the research queue wait when the fleet is full.

Prewarmed inboxes arrive with sender history; fresh inboxes are warmed by us for 14 to 21 days before handover. Our warmup then keeps running at 30 emails per inbox per day underneath Grok’s sending for as long as you hold the inboxes. There is nothing in the agent to switch off, and nothing to add.

Replies falling on one mailbox while the rest hold, bounces climbing on one domain: take that mailbox out of rotation, run the blacklist checker and the bounce analyzer on its bounces, and message us on WhatsApp at +1 904 736 2539. Replacement inboxes are part of the package when deliverability drops, and a few spare mailboxes connected are what make a flagged one an inconvenience rather than a stopped agent.

Prewarmed inboxes include a free prewarmed .COM or .CO domain and send from the day they land: $8.00 per inbox per month on Google and Microsoft, $7.00 on a two-month commit, $6.00 quarterly. Azure is billed per tenant, $69 monthly, $60 on two months, $50 quarterly, with up to 100 inboxes on one domain, which at capacity is $0.69, $0.60 and $0.50 per inbox. Fresh inboxes on your own branded domains, warmed for 14 to 21 days first, run $3.50 to $2.00 per inbox per month on Google, $3.00 to $2.00 on Microsoft 365, and $50 flat for an Azure tenant. Every price is at /price.md, and how it works covers everything between paying and the first send.

Can Grok send cold email from WarmInboxes mailboxes?

Yes. Every mailbox we deliver is an official Google Workspace, Microsoft 365 or Azure account with you as admin, and Grok connects to Google Workspace and Microsoft 365 accounts to read, draft, schedule and send mail. Connect the mailbox the way you would connect any Workspace or 365 account, and Grok sends from it, through Google or Microsoft, not through anything of ours.

Does anything at WarmInboxes connect to Grok?

No. Grok has no connector into our API or MCP servers and we do not claim one. The mailbox connection is Grok’s own, made by you as the mailbox admin. The free deliverability checks are a keyless HTTP API, described at warminboxes.com/openapi.json, that any agent can call.

How many emails a day can Grok send per mailbox?

About fifteen a day on Google Workspace, eight on Microsoft 365, two on a full Azure tenant of 100. The figure is the receiving server’s tolerance for one new mailbox, and an agent does not change it. Give Grok the cap as a standing instruction, have it schedule sends across the day, and size the fleet so the instruction is easy to keep.

Does one-to-one email still need warmed mailboxes?

Yes. A receiving server judges the domain and the mailbox before it reads the email, and the best-researched message from a cold domain lands where a template does. Prewarmed mailboxes arrive with sender history; fresh ones are warmed for 14 to 21 days first, and our warmup keeps running underneath at 30 emails per inbox per day for as long as you hold them.

How does Grok handle replies and unsubscribes?

Through the same connection: it can read the mailbox it sends from. Instruct it to check for replies, out-of-office and unsubscribes before each run, stop writing to anyone who has answered or asked out, and keep the suppression list it builds. An agent that sends and never reads is how a researched campaign collects complaints.

How fast do the mailboxes arrive?

Within 48 to 72 hours of payment, prewarmed and fresh alike, with SPF, DKIM, DMARC and forwarding configured before you log in. Prewarmed means no warmup wait once they land, not that they are delivered the same day.