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Mailboxes for Instantly

Instantly Mailboxes: Add, Warm Up & Scale

To add email accounts to Instantly, connect Google or Microsoft mailboxes from the Email Accounts tab by OAuth. Jetmail builds those mailboxes, with domains and DNS, and connects them to Instantly in one click.

Jetmail · Connect to Instantly
InstantlyConnect with OAuth

Warmup switches on inside Instantly after connecting.

Setup

How to add mailboxes to Instantly

Instantly mailboxes can come from two places: accounts you buy inside Instantly, or Google Workspace and Microsoft 365 mailboxes you bring yourself. Bringing your own takes five steps with Jetmail.

  1. Step 1

    Buy domains

    Lookalike domains, registered to you, in the Jetmail dashboard.

  2. Step 2

    Create mailboxes

    About 3 Google or Microsoft mailboxes per domain.

  3. Step 3

    Auto DNS

    SPF, DKIM, DMARC and MX published for you.

  4. Step 4

    1-click OAuth

    Connect every mailbox to Instantly at once.

  5. Step 5

    Warm up & send

    Warm up, or start pre-warmed at about 30/day.

Instantly's own connection methods, from its help center (October 2026)
MethodWhat you do in InstantlyWhat has to be ready first
Google, OAuthConnect existing accounts → Google → Option 1: oAuth → LoginA Workspace admin adds Instantly as a trusted app under Security → Access and data control → API controls
Google, app passwordConnect existing accounts → Google → app password option2-Step Verification on for each account (Google prefers OAuth)
Microsoft 365 / OutlookConnect existing accounts → Office 365 / Outlook → sign inSMTP and IMAP enabled in the Microsoft admin center
Jetmail mailboxesNothing: connect from Jetmail with 1-click OAuthNothing: DNS and mailbox settings are done for you

Instantly login

Log in to Instantly and add your accounts

The Instantly login page is app.instantly.ai. Once you're signed in, adding an account takes a few clicks.

  1. Go to app.instantly.ai and sign in with your Instantly email and password.
  2. Open the Email Accounts tab and click Add or Buy Accounts.
  3. Choose Connect existing accounts, then Google or Office 365 / Outlook.
  4. Sign in to the mailbox in the pop-up and accept the permissions. If an account isn't listed, pick "Use another account".
  5. Repeat for each mailbox, then open each account's settings and switch warmup on.

With dozens of mailboxes, steps 3–5 are where the time goes. Jetmail connects all of them by OAuth from one screen, the same way it does for Smartlead and 50+ other tools.

Instantly domains

Instantly DFY accounts vs your own mailboxes

Instantly sells done-for-you and pre-warmed Google accounts. Here's how they compare with bringing your own through Jetmail, using each provider's published terms (October 2026).

Instantly DFYJetmail
Google mailboxes$5/mailbox (done-for-you)$39/mo for 10 · $99/mo for 30 · $299/mo for 100 (extra $3.50–$3.00)
Microsoft mailboxesNot offeredSame price as Google
Pre-warmed$10/mailbox, Google only, batches of 5Google & Microsoft: $39 for 3 · $149 for 12 · $339 for 30 first month, then $6–$8/mailbox
Domains$15/yr; Instantly keeps ownership and won't transferBring your own or buy in the dashboard; registered to you
MinimumPaid Instantly plan required (from $47/mo)10 mailboxes (Starter)
Where they workBuilt into Instantly; needs a paid Instantly plan50+ (Instantly, Smartlead, …)

Monthly cost of 30 mailboxes

Mailboxes only, billed monthly, domains excluded. Jetmail pre-warmed is shown at its price after the first month. Instantly accounts also need a paid Instantly sending plan (from $47/mo), not included above.

Monthly cost of 30 mailboxes
Instantly DFY$150
Jetmail$99
Instantly pre-warmed$300
Jetmail pre-warmed$180

What is a forwarding domain in Instantly?

In Instantly's done-for-you setup, the forwarding domain is an optional field where you enter your main website's domain. Anyone who types one of your secondary sending domains into a browser is redirected to your real site. It doesn't touch email: replies still land in the mailbox that sent the message. Instantly's DFY setup supports .com and .org domains only and creates up to 5 accounts per domain. With Jetmail, domains are registered to you at $15/year each, so you can set up the same website redirect at your DNS host and keep the domains if you change tools. More on picking them in cold email domains.

Instantly email warmup

Instantly warmup settings, explained

Turning on warmup adds a mailbox to Instantly's pool of warmup accounts, which send to each other, open, reply and pull messages out of spam. These are the settings Instantly pre-fills for a new account.

SettingWhat it doesInstantly's suggestion
Increase per dayAdds warmup emails one day at a time1
Daily warmup limitMost warmup emails sent per day10 for new accounts
Reply rate %Share of warmup emails that get a reply30 for new accounts
Disable slow warmupSkips the gradual rampOnly for accounts that are already warm
Warmup filter tagKeeps warmup emails out of your main inboxDefault or random tag
Weekdays only modeSends warmup emails Monday to FridayOptional

Instantly asks you to wait at least 2 weeks, with a warmup health score above 90%, before a new account sends campaigns. Leave warmup running at a low level afterwards. The full week-by-week schedule is in the email warmup guide.

Instantly pre-warmed accounts, without the lock-in

Jetmail's pre-warmed inboxes come in Google and Microsoft, on domains you own, and connect to Instantly with OAuth on day one.

Checklist

Before your first Instantly campaign

  1. Send from lookalike domains, never your main company domain.
  2. Keep about 3 mailboxes per domain and about 30 cold emails per mailbox per day.
  3. Check SPF and DMARC pass with the SPF checker and DMARC checker.
  4. Warm up new mailboxes for at least 2 weeks, or start with pre-warmed ones.
  5. Set a custom tracking domain in Instantly if you track links.

Need the full stack? See cold email infrastructure or compare plans on the pricing page.

Sources: Instantly pricing · Instantly: connect Google via OAuth · Instantly: connect Google via app password · Instantly: connect Microsoft 365 · Instantly: DFY email setup · Instantly: pre-warmed accounts · Instantly: how warmup works · Instantly: warmup settings

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Frequently asked questions

How do I add email accounts to Instantly?

In Instantly, open Email Accounts, click Add or Buy Accounts, choose Connect existing accounts and pick Google or Office 365 / Outlook. Google accounts connect by OAuth (after a Workspace admin trusts Instantly's app) or with an app password; Microsoft accounts connect by signing in once SMTP and IMAP are enabled.

What is a forwarding domain in Instantly?

It's an optional field in Instantly's done-for-you domain setup. You enter your main website's domain, and anyone who visits one of your secondary sending domains is redirected there. It only affects website visitors; it doesn't forward email or change where replies go.

Does Instantly include email warmup?

Yes. As of October 2026, every Instantly plan includes automated warmup, and the Growth plan lists unlimited email accounts and warmup. Instantly recommends waiting at least 2 weeks, with a warmup health score above 90%, before using a new account in campaigns.

What are Instantly pre-warmed accounts?

Google accounts Instantly has already warmed, sold at $10 per account per month in batches of 5, plus $15 per domain per year. Instantly keeps ownership of the domains and the accounts only work inside Instantly.

How do I log in to Instantly?

Go to app.instantly.ai and sign in with your Instantly account. Your mailboxes are connected from the Email Accounts tab once you're in. If you use Jetmail, you never share mailbox passwords with Instantly: the connection is made by OAuth.

Can I use my own Google and Microsoft mailboxes in Instantly?

Yes. Jetmail creates Google Workspace and Microsoft 365 mailboxes on domains registered to you, publishes SPF, DKIM, DMARC and MX, and connects them to Instantly with 1-click OAuth. Because you own the domains, you can move the same mailboxes to another sending tool later.

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