How to Connect Gmail to Smartlead (Google Workspace and Free Gmail)

To connect Gmail to Smartlead, use Google OAuth for Google Workspace mailboxes and SMTP with an app password for free @gmail.com accounts. OAuth needs a one-time approval in the Google Admin Console, where a Workspace admin marks Smartlead as a trusted app. Free Gmail needs 2-Step Verification, a 16-character app password and the SMTP and IMAP settings listed below.

Last updated: October 2026. Prices checked against Smartlead’s official pricing page.

Which Gmail connection method should you use?

The right connection method depends on the account type. Google Workspace mailboxes should use Google OAuth, which Smartlead’s help center calls the more secure and reliable option, while free @gmail.com addresses cannot use OAuth at all and must connect through SMTP and IMAP with an app password generated in the Google account.

“a way for internet users to grant websites or applications access to their information”

Source: Wikipedia, OAuth

That is the practical difference: OAuth grants Smartlead access without storing the mailbox password, while SMTP relies on an app password that Smartlead keeps on file.

Source: Smartlead help center articles 18 (Google OAuth), 4 (Gmail SMTP) and 163 (free Gmail), checked October 2026.

For any business sending domain, OAuth is the default choice, and SMTP is the fallback for personal Gmail.

What do you need before you connect Gmail to Smartlead?

Before you connect Gmail to Smartlead, confirm who controls the Google account and what access they have. Workspace OAuth needs an admin who can approve third-party apps, while the SMTP route needs the mailbox owner to change security settings. Both need the sending domain authenticated first.

There are five prerequisites to check before starting:

• Google Workspace admin access: A Super Admin, or an admin with rights to approve third-party apps, who can mark Smartlead as trusted in the Admin Console.
• Browser pop-ups allowed: Permission for pop-ups on Smartlead, since both the Client ID screen and the Google consent screen open in pop-up windows.
• Authenticated sending domain: SPF, DKIM, DMARC and MX records on the domain, which Smartlead treats as the baseline for every sending mailbox.
• 2-Step Verification for SMTP: Required on the Google account before Google offers the App passwords option used by the free Gmail method.
• IMAP access enabled: On by default for personal Gmail; for Workspace, controlled under Apps, Google Workspace, Gmail, End User Access.

With these in place, the OAuth flow below usually completes in one pass.

Step 1: Start the Google OAuth connection in Smartlead

The Google OAuth connection is started from Smartlead’s Email Accounts page and uses Smartlead’s own pre-verified Google app, so no Google Cloud project is needed. The first screen shows a Client ID that the Workspace admin will paste into the Admin Console in the next step.

1. Open Email Accounts in the left sidebar and click + Connect Mailbox.
2. Choose Smartlead’s Infrastructure as the infrastructure type, then pick Google OAuth as the provider.
3. Copy the Client ID shown in the pop-up.
4. Click the Admin Panel link in the same pop-up to open the Google Admin Console.

Some help center screenshots label these buttons Add Account and Shared Infrastructure; they lead to the same Google option. The other infrastructure type, Your Email Network, is a private OAuth setup available only on the Unlimited Smart and Prime plans, as listed in the Smartlead plan-by-plan pricing guide.

Step 2: Mark Smartlead as trusted in the Google Admin Console

Trusting Smartlead is a one-time Google Workspace admin action that allows any user on the domain to connect a mailbox through OAuth. It happens at admin.google.com under API Controls, and until it is done Google shows a This app is blocked error to anyone who tries to connect.

Smartlead’s OAuth help article lays out the admin path in order. There are five admin actions:

1. Open API Controls: In admin.google.com go to Security, then Access and Data Control, then API Controls, and select Manage App Access.
2. Configure New App: Click Configure New App and paste the Smartlead Client ID copied earlier into the search bar to find the Smartlead app.
3. Choose the scope: Select the Smartlead app and apply access to all users in the organization or to a specific organizational unit, then click Continue.
4. Mark as Trusted: Select Trusted so Workspace recognizes Smartlead as an approved third-party application, then click Continue and review the summary.
5. Finish and wait: Click Finish and allow up to 10 minutes for the change to propagate across the Workspace domain before retrying.

Once trusted, every user on that domain can connect a mailbox without repeating the admin step.

Step 3: Authorize the mailbox and confirm it is connected

Authorizing the mailbox is the final OAuth step, where the mailbox owner signs in to Google and approves the permissions Smartlead requests. Those permissions cover the Gmail API, sending mail and reading the basic profile, and approval returns the user to Smartlead with the mailbox marked as connected.

1. Return to Smartlead’s Email Accounts page and start the Google connection again.
2. Click Connect Account; the Google consent screen opens in a new pop-up.
3. Select the Google Workspace account to connect.
4. Review the permissions (Gmail API, send mail, read profile) and click Allow.
5. Wait for the redirect; the mailbox shows a green Connected status.

Repeat the same five actions for every Workspace mailbox. Each connection is done once per inbox.

How do you connect a free Gmail account?

A free Gmail account connects to Smartlead through SMTP and IMAP rather than OAuth, because Smartlead’s help center states that free @gmail.com addresses cannot use the OAuth flow. The method uses a Google app password, which only appears after 2-Step Verification is turned on.

“Google OAuth is the more secure and reliable method”

Source: Smartlead help center, Connect Gmail with SMTP (helpcenter.smartlead.ai/en/articles/4-connect-gmail-with-smtp)

The help article still documents the SMTP route for accounts that cannot use OAuth. There are five steps, in order:

1. Confirm IMAP: Check that IMAP is enabled; it is on by default for personal Gmail and set by the admin under End User Access for Workspace.
2. Turn on 2-Step Verification: Go to myaccount.google.com, open Security, select 2-Step Verification, click Get Started and complete the Turn On flow.
3. Generate an app password: Under Security and 2-Step Verification, open App passwords, choose Mail and a custom name such as Smartlead, then click Generate.
4. Add the account in Smartlead: On the Email Accounts page add the account with the Gmail address and the 16-character app password, never the regular password.
5. Enter server settings and test: Fill in the SMTP and IMAP hosts and ports from the table below, then click Test Connection to receive a confirmation email.

If the Test Connection email arrives, the mailbox is ready for warmup.

What are the Gmail SMTP and IMAP settings for Smartlead?

The Gmail server settings for Smartlead are smtp.gmail.com on port 465 with SSL for sending and imap.gmail.com on port 993 with SSL for reading replies. These values come from Smartlead’s Gmail SMTP help article and are entered together with the app password when adding the account.

Source: Smartlead help center, Connect Gmail with SMTP (article 4), checked October 2026.

Every value is fixed for Gmail, so a failed test almost always means a wrong password or a disabled setting rather than a wrong host.

For other SMTP providers such as Zoho or Amazon SES, Smartlead’s mailbox guide suggests trying port 587 with TLS or port 465 with SSL if the first attempt fails.

What should you set up right after connecting?

A newly connected Gmail mailbox is ready to send but not ready for cold campaigns. Smartlead’s guidance is to warm it up, keep volume low and set up tracking on a custom domain before assigning it to a campaign, so the first days of a mailbox are about reputation rather than outreach.

There are five follow-up tasks after the green Connected status appears:

• Enable warmup: Open the mailbox’s Warm-up tab and toggle Enable Warmup, with Daily Ramp-Up switched on at the same time for fresh domains.
• Custom tracking domain: A CNAME record with host emailtracking pointing to open.sleadtrack.com, which avoids the shared tracking links that can hurt deliverability.
• Warmup identifier filter: A Gmail filter on the mailbox’s two-word custom warm-up identifier that labels or archives warmup emails without ever deleting them.
• Conservative daily limit: A modest campaign limit that keeps campaign and warmup emails together near the 50 per day ceiling Smartlead recommends per mailbox.
• Campaign assignment: Adding the warmed mailbox on a campaign’s Email Accounts tab so Smartlead can rotate sending across it with other mailboxes.

The Smartlead warmup settings guide covers the Warm-up tab in detail, and inbox rotation explained shows why several mailboxes per campaign help. Warm first, assign later.

How many emails can a Gmail mailbox send in Smartlead?

A Gmail mailbox in Smartlead should send about 50 emails per day once warmed, according to Smartlead’s API documentation. Its troubleshooting article goes further and recommends keeping outbound plus warmup at 50 in total per mailbox, with at least five minutes between sends, to avoid quota-exceeded errors.

Source: Smartlead API docs, email accounts (api.smartlead.ai/core/email-accounts) and help center article 22, checked October 2026.

The safe number for a Gmail mailbox is roughly 50 emails a day including warmup, so volume grows by adding mailboxes rather than by pushing one harder.

Every plan includes unlimited mailboxes, which makes adding inboxes the cheaper path to more volume. A full setup walkthrough is in the guide on how to use Smartlead from account to launch.

How do you fix common Gmail connection errors?

Most Gmail connection errors in Smartlead come from a missing admin approval, a blocked pop-up or a Google security setting that is turned off. Smartlead’s help center documents the fix for each, and none of them require contacting Google; they are settings on the Workspace or account side.

There are six errors that come up most often:

• This app is blocked: Google’s message when Smartlead is not yet trusted in the Admin Console; approve the app, wait a few minutes and retry.
• Consent window never opens: A browser pop-up blocker stopping the Google consent screen, fixed by allowing pop-ups for Smartlead and clicking Connect Account again.
• Still blocked after approval: Propagation delay, since the trust setting can take up to 10 minutes to reach every user on the Workspace domain.
• App passwords option missing: 2-Step Verification not yet enabled on the Google account, which hides the App passwords page completely.
• Test Connection fails: A regular password used instead of the app password, or IMAP disabled for the account by the Workspace admin.
• Sending quota exceeded: Too many emails per mailbox; Smartlead suggests 50 in total including warmup, five-minute gaps and moving SMTP mailboxes to OAuth.

If an error persists after these checks, Smartlead’s chat support asks for a screenshot of the message. Spam-folder issues after connecting are covered in why Smartlead emails go to spam.

Connecting Outlook and other providers

Outlook and Microsoft 365 mailboxes connect to Smartlead through their own OAuth flow, and any other provider connects through SMTP. Google, Outlook and SMTP mailboxes can all sit in the same Smartlead account, which suits teams that send from more than one email provider at once.

For Microsoft 365, an admin first opens admin.microsoft.com, goes to Users, Active Users, selects the user, opens the Mail tab and Manage Email Apps, ticks Authenticated SMTP and IMAP, saves and waits 20-30 minutes. The user then picks Outlook under Smartlead’s Infrastructure, signs in and accepts the permissions. Bulk upload is not available for Outlook, while SMTP mailboxes support a bulk upload method.

Providers not listed, such as Zoho, FastMail or Amazon SES, use the SMTP option with their own host and port values.

Bottom line: which way should you connect Gmail?

Google OAuth is the best way to connect Gmail to Smartlead for any Google Workspace mailbox, because it skips stored passwords and only needs one admin approval per domain. SMTP with an app password is the fallback for free Gmail accounts, using smtp.gmail.com on port 465 and imap.gmail.com on port 993.

“Connect with OAuth, warm up for two weeks, then let rotation spread the volume.”

Source: GrowthStackKit, Smartlead Review

After connecting, the work moves to warmup and campaign building, covered in the Smartlead sequence building guide. For the bigger picture on whether the platform fits, read the full Smartlead review.

Frequently asked questions

The 12 most-asked questions about connecting Gmail to Smartlead.

Can I connect a free Gmail account to Smartlead with OAuth?

No. Smartlead’s help center states that free @gmail.com accounts cannot use Google OAuth because the flow needs an admin login. Free Gmail connects through SMTP and IMAP with a 16-character app password, which requires 2-Step Verification on the Google account.

Do I need a Google Workspace admin to connect Gmail to Smartlead?

For Google OAuth, yes, once per domain. A Super Admin or an admin with rights to approve third-party apps must mark Smartlead as Trusted in the Google Admin Console. After that, every user on the domain can connect a mailbox without the admin.

Why does Google say This app is blocked when I connect Smartlead?

Google shows that message when Smartlead has not been added as a trusted app in the Workspace Admin Console. The admin needs to configure Smartlead under API Controls and Manage App Access, mark it as Trusted, then wait up to 10 minutes before retrying.

What are the Gmail SMTP settings for Smartlead?

Use smtp.gmail.com on port 465 with SSL set to true for sending, and imap.gmail.com on port 993 with SSL set to true for reading. Enter the Gmail address and the 16-character app password, not the regular password, then click Test Connection.

How do I create a Google app password for Smartlead?

Turn on 2-Step Verification first at myaccount.google.com under Security. Then open 2-Step Verification, scroll to App passwords, choose Mail and a custom name such as Smartlead, click Generate and copy the 16-character password into Smartlead. Use that password in Smartlead instead of the regular Gmail password.

Is Google OAuth or SMTP better for Smartlead?

Smartlead recommends Google OAuth as the more secure and reliable method. It does not require storing a password and reduces the risk of disconnection when security policies change. SMTP with an app password is the fallback for free Gmail accounts.

How long does it take to connect a Gmail account to Smartlead?

Smartlead’s help center says a mailbox connection takes under two minutes per inbox. The first Workspace connection can take longer because the admin approval may need up to 10 minutes to propagate across the domain. After that, each additional mailbox on the domain connects without the admin.

How many Gmail accounts can I connect to Smartlead?

Every Smartlead plan includes unlimited email accounts with no per-mailbox fee, and the 14-day free trial also allows unlimited mailbox connections. Gmail, Outlook and SMTP mailboxes can be connected in the same account. There is no per-mailbox or per-seat charge on any plan.

How many emails per day can a Gmail mailbox send through Smartlead?

Smartlead’s API documentation suggests 50 per day for a Gmail mailbox. Its quota troubleshooting article recommends keeping campaign emails plus warmup at 50 in total per mailbox, with at least five minutes between sends. More volume should come from adding mailboxes, not from raising one mailbox’s limit.

Do I need a Google Cloud project to connect Gmail to Smartlead?

No. With Smartlead’s Infrastructure option, Google OAuth uses Smartlead’s own pre-verified Google app, so no Google Cloud project is needed. A private OAuth setup called Your Email Network exists only on the Unlimited Smart and Prime plans. The Workspace admin only needs to trust the app once.

What should I do after connecting Gmail to Smartlead?

Enable warmup on the mailbox’s Warm-up tab, turn on Daily Ramp-Up for fresh domains, set up a custom tracking domain, create a filter on the warm-up identifier and wait at least two weeks before assigning the mailbox to a campaign.

Can I connect Outlook and Gmail in the same Smartlead account?

Yes. Google OAuth, Outlook and SMTP mailboxes can all be connected to the same Smartlead account at the same time. Microsoft 365 mailboxes need an admin to enable Authenticated SMTP and IMAP first, and bulk upload is not available for Outlook.