Inboxes for Clay

Clay was where a list got found, enriched and scored, and then exported to whatever sent it. With Clay’s own Sequencer the export step goes away: the segment you built syncs straight into a campaign. What it still needs is mailboxes to send from, and the choice is between the email accounts Clay sells and mailboxes you own and connect.

This page is about the second. We build the mailboxes, not the sequencer, and this is not a review of Clay. Every figure here is ours and checkable against the calculator, the placement log and the price list.

Clay already knows a lot about every row by the time it reaches the Sequencer. The one thing worth adding is the provider behind each address, because it decides which mailboxes should send to it. Google-hosted recipients are sent from Google Workspace; everyone else (Microsoft 365, other providers and gateway-protected domains) from Azure. The reason is in the placement log, measured monthly.

Run the export through the ESP segmenter to split it by provider, then build one segment per provider in Clay and give each its own campaign and its own senders. The ESP calculator sizes the mailboxes for each split from the same file.

• Real mailboxes, your admin. Every inbox we deliver is an official Google Workspace, Microsoft 365 or Azure mailbox with you as admin. Clay connects to it the way it connects to any business mailbox.
• The Sequencer app authorised on Google. A Workspace admin approves Clay’s Sequencer app in the Google Admin console before the first mailbox on the domain connects. Do it first and the “access blocked” screen never appears.
• Authentication already published. SPF, DKIM, DMARC and forwarding are configured before handover. Confirm it with the authentication checker.
• Emails verified close to the send. An address found by enrichment is a fact about when it was found. Verify it near the send with the email verifier or a verification waterfall, because bounces are the signal that burns a new mailbox fastest.
• Two-factor decided. Disable 2FA on the receiving account before delivery day, or keep it on and grant restricted sub-account access to [email protected].

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

1. 1Google Workspace mailboxes over Google OAuth. After the admin step above, each mailbox signs in once. No password stored and no authenticator per mailbox; OAuth vs app passwords covers what still means reconnecting.
2. 2Microsoft 365 and Azure mailboxes over Microsoft OAuth. The Outlook path. Microsoft has retired basic IMAP sign-in, so OAuth is the one that keeps working.
3. 3Or many at once with a bulk SMTP/IMAP upload. Clay takes a CSV of SMTP and IMAP credentials, which is the quick way in for a large order. On Microsoft, enable SMTP AUTH first, at the tenant and per mailbox: it is off by default and fails looking exactly like a wrong password.
4. 4Assign senders to campaigns by provider. Google mailboxes on the Google-hosted segment, Azure on the rest, so the routing above survives into the send.
5. 5Tracking on your own domain, or off. A shared tracking domain joins the reputations you separated. A custom domain, or no open tracking; we turned ours off and published the result.

Size the fleet for the volume with the calculator. If the enrichment bill is the bigger worry, where Clay credits go and cost per qualified lead are the two articles to read before the first campaign.

Prewarmed inboxes arrive with sender history; fresh inboxes are warmed by us for 14 to 21 days after delivery, before you send. Once the inboxes are connected to your sequencer, its own warmup is switched on and runs alongside your campaigns, and we switch ours off, so the mailboxes are never warmed by two systems at once. Count warmup mail inside the daily cap: it is real mail from the same mailbox.

One sender’s replies falling while the rest hold, bounces climbing on one domain: take that mailbox out of the campaign, check its domain with the blacklist checker, run its bounces through the bounce analyzer to tell the list from the domain, and message us on WhatsApp at +1 904 736 2539. Outside the 7-day placement replacement guarantee, a flagged mailbox is not replaced for free; what every order comes with is the free deliverability tools to find the cause while it is one mailbox.

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 I use my own inboxes with the Clay Sequencer?

Yes. Alongside the email accounts Clay sells, the Sequencer connects mailboxes you already own: Google Workspace and Microsoft over OAuth, and other providers over SMTP/IMAP, one at a time or as a bulk CSV upload. Our mailboxes are official Google Workspace, Microsoft 365 and Azure accounts with you as admin, so they connect the way any business mailbox does.

Do you load the inboxes into Clay for me?

Clay is not one of the sequencers our portal exports into directly (those are Instantly, Smartlead, PlusVibe and EmailBison). You get full admin on every mailbox and the credentials to connect them over OAuth or a bulk SMTP/IMAP upload, and if you would rather we did it by hand, ask on WhatsApp.

Why does Google say access is blocked when I connect a mailbox to Clay?

Before the first mailbox on a Google Workspace domain connects over OAuth, a Workspace admin has to authorise the Clay Sequencer app in the Google Admin console. On our inboxes you are that admin, so it is a one-off step per Workspace, done before the first connection rather than after the error. If the mailbox sits in a sub-organisation, check the authorisation covers it.

What daily limit should each mailbox have in Clay?

Fifteen a day on Google Workspace, eight on Microsoft 365, two on a full Azure tenant of 100. Clay paces sends across the connected accounts; the cap per mailbox is still the number that decides whether the fleet lasts, and it is the one to set before the first campaign.

Do prewarmed inboxes need warmup in Clay?

Yes, keep it on. Prewarmed inboxes arrive with sender history, so they send from the day they land rather than after a new account's warmup wait. Once the inboxes are connected to your sequencer, its own warmup is switched on and runs alongside your campaigns, and we switch ours off, so the mailboxes are never warmed by two systems at once. Count warmup mail inside each mailbox's daily cap.

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.