Email Marketing Overview

OneTap Login PRO can automatically subscribe new Google users to your email marketing list. Choose from 5 popular email service providers (ESPs) with built-in GDPR compliance features.

PRO Feature

Email Marketing integration is a PRO feature. Upgrade to PRO to unlock this functionality.

Supported Providers

Provider	Features	Double Opt-in
MailChimp	Lists, tags, merge fields	Yes
MailerLite	Groups, custom fields	Yes
Brevo	Lists, DOI templates, SMS	Yes
Klaviyo	Lists, profiles, events	Yes
GetResponse	Campaigns, tagging	Yes

How It Works

User signs in with Google
        ↓
Account created/logged in
        ↓
Check: Marketing consent given?
        ↓
    YES → Subscribe to email list
        ↓
    NO → Skip subscription

Configuration

Accessing Settings

1. Go to Settings > OneTap Login
2. Click Integrations tab
3. Find Email Marketing section

Basic Setup

1. Enable Email Marketing: Toggle on
2. Select Provider: Choose from dropdown
3. Enter API Key: From your ESP
4. Enter List ID: Target list/audience
5. Save Changes

Provider Dropdown

GDPR Compliance

Double Opt-in (DOI)

All providers support double opt-in:

1. User signs up
2. Added to list as "pending"
3. Confirmation email sent
4. User clicks confirm link
5. Status changes to "subscribed"

Marketing Consent

Enable the consent requirement:

Settings > Users > Marketing Consent

☑ Require marketing consent before subscribing

See Marketing Consent for details.

Consent Modes

Mode	Behavior
Disabled	Subscribe all users automatically
Checkbox	User must check consent box
Explicit popup	Modal consent dialog

Data Sent to ESP

When subscribing, OneTap Login sends:

Field	Description
Email	User's email address
First Name	From Google profile
Last Name	From Google profile
Source	"google_signup" or custom

Custom Fields (varies by provider)

Some providers accept additional data:

• Registration date
• Website URL
• Custom tags

Provider Comparison

Features

Feature	MailChimp	MailerLite	Brevo	Klaviyo	GetResponse
Free tier	500 contacts	1,000 contacts	300 emails/day	250 contacts	500 contacts
Tags	Yes	No	Yes	Yes	Yes
Segments	Yes	Yes	Yes	Yes	Yes
Automations	Yes	Yes	Yes	Yes	Yes
Landing pages	Yes	Yes	Yes	No	Yes
SMS	No	No	Yes	Yes	No

Best For

Provider	Best For
MailChimp	Beginners, established brand
MailerLite	Budget-conscious, simplicity
Brevo	Transactional + marketing, SMS
Klaviyo	E-commerce, advanced segmentation
GetResponse	Webinars, all-in-one marketing

Integration Flow

New User Registration

1. User registers via Google
2. OneTap creates WordPress account
3. Check marketing consent (if enabled)
4. If consent given:
   a. Call ESP API
   b. Add subscriber with data
   c. Trigger DOI if enabled
5. Log subscription result

Returning User Login

By default, returning users are NOT re-subscribed:

• Only new registrations trigger subscription
• Prevents duplicate subscriptions
• Respects unsubscribes in ESP

Testing Integration

Test Connection

Each provider section has a Test Connection button:

1. Enter API credentials
2. Click Test Connection
3. Verify success message

Verify Subscription

1. Create test account via Google sign-in
2. Check ESP for new subscriber
3. Verify DOI email sent (if enabled)
4. Confirm data fields populated

Troubleshooting

User Not Subscribed

Causes:

1. Marketing consent not given
2. API credentials invalid
3. List ID incorrect
4. User already exists in list

Solutions:

1. Check consent settings
2. Verify API key
3. Verify list/audience ID
4. Check ESP for existing subscriber

API Error

Common errors:

Error	Solution
401 Unauthorized	Check API key
404 Not Found	Check list ID
400 Bad Request	Check email format
429 Rate Limited	Wait and retry

DOI Email Not Sent

Causes:

1. DOI not enabled in ESP
2. User already confirmed
3. Email in ESP suppression list

Solutions:

1. Enable DOI in ESP settings
2. Check subscriber status
3. Review ESP suppression list

Privacy & Legal

What's Stored

OneTap Login stores:

• Subscription status
• Consent timestamp
• ESP subscriber ID

What's Sent

Only essential data sent to ESP:

• Email (required)
• Name (optional)
• Tags (optional)

GDPR Requirements

To be GDPR compliant:

• Enable marketing consent
• Use double opt-in
• Provide unsubscribe option
• Document consent

CAN-SPAM / CASL

For North American compliance:

• Include physical address in emails
• Provide unsubscribe mechanism
• Honor unsubscribes within 10 days

Next Steps

Choose your provider:

• MailChimp Setup
• MailerLite Setup
• Brevo Setup
• Klaviyo Setup
• GetResponse Setup

Or configure consent:

• Marketing Consent