Double Opt-In (DOI) is a two-step email subscription process that ensures subscribers genuinely want your emails. When someone signs up, they receive a confirmation email and are only added to your list after clicking the confirmation link. This helps keep your list clean and engaged, reducing spam complaints and improving email deliverability.
The Double Opt-In flow: a customer subscribes, receives a confirmation email, clicks to confirm, and is then added as a subscribed contact.
What is Double Opt-In?
With Double Opt-In enabled:
Customer subscribes - Enters their email on your sign-up form
Confirmation email sent - They receive an email asking them to confirm
Customer confirms - They click the confirmation link
Subscription active - Only then are they added as a subscribed contact
Benefits
Benefit | Description |
Higher engagement | Confirmed subscribers are more likely to open and click |
Better deliverability | Lower bounce rates and spam complaints |
Compliance | Meets GDPR and other regulatory requirements |
Clean list | No fake emails, typos, or accidental sign-ups |
Subscription States
State | In Shopify | In Brevo PushOwl | Can Receive Marketing? |
Signed up, not confirmed | Pending | Blocklisted | No |
Confirmed | Subscribed | Subscribed | Yes |
Opted out | Unsubscribed | Unsubscribed | No |
For full details on how customer subscription states are synced from Shopify, see Customer Data Reference.
When to Use DOI
Double Opt-In is Recommended When
You operate in regions with strict regulations (e.g., GDPR in the EU) that require explicit consent
You want a high-quality list: confirmed subscribers have higher open and click rates
You're experiencing spam complaints: DOI eliminates fake or mistyped email addresses
You're building a long-term email program: a smaller, engaged list outperforms a large, unengaged one
When Single Opt-In May Be Better
You prioritize list growth speed: single opt-in has no confirmation step, so more people complete the sign-up
Your audience is less likely to confirm: some customer segments may not check for confirmation emails
You have other list hygiene measures: such as regular list cleaning or engagement-based filtering
Tip: You can start with single opt-in and switch to double opt-in later. Existing subscribers won't need to re-confirm.
Setting Up Double Opt-In
You can enable and configure DOI from Opt-in Settings in Brevo PushOwl.
Configuration Options
Setting | Description |
Enable double opt-in | Toggle DOI on or off |
Opt-in email template | The email asking customer to confirm (e.g., "Default DOI Template") |
Allowed tags | Only trigger DOI for customers with specific Shopify tags |
Confirmation URL | Custom page to redirect subscribers to after they confirm |
Confirmation email | Optional final confirmation email sent after the subscriber has opted in |
The Templates page in Brevo PushOwl where you can manage and customize your DOI email templates.
Email First: Optimize Double Opt-In Collection
When double opt-in is enabled, email will be collected before SMS. This ensures unified customer profiles and streamlined communication by enabling accurate contact merging.
Allowed Tags
You can restrict DOI to only apply to customers with specific tags on Shopify. Customers with these tags will be synced with double opt-in. This is useful if you only want DOI for certain customer segments.
Confirmation URL
Optionally, you can set a custom page where subscribers will be redirected after confirming their subscription, such as a thank-you page or a special offer page on your store.
Confirmation Email
You can enable a final confirmation email that goes out to all subscribers who have opted in for email marketing. This is separate from the initial DOI confirmation. It's a "thank you for subscribing" message.
Important: Bulk Importing Customers
Brevo PushOwl relies on customer webhooks sent by Shopify to send confirmation emails to your customers. If you're planning to bulk upload customers to Shopify, please turn off double opt-in first. Otherwise, all imported customers will receive DOI confirmation emails.
Best Practices
Send immediately: Confirmation email should arrive promptly
Clear subject line: "Please confirm your subscription" works well
Simple design: One clear call-to-action button
Explain benefits: Remind them why they signed up
Mobile-friendly: Many will confirm on their phone
Set expectations: Tell customers to check their inbox (and spam folder)
Troubleshooting DOI
Shopify DOI vs. Brevo PushOwl DOI
Both Shopify and Brevo PushOwl offer their own double opt-in mechanism. It is recommended to use either Shopify's DOI or Brevo PushOwl's DOI, not both at the same time. Enabling DOI in both platforms can result in customers receiving duplicate confirmation emails and conflicting subscription states.
If you use Brevo PushOwl DOI, disable Shopify's built-in double opt-in
If you use Shopify DOI, disable Brevo PushOwl's double opt-in from Opt-in Settings
Customers not receiving confirmation emails
If subscribers are not receiving their DOI confirmation emails:
Check that double opt-in is enabled in Opt-in Settings
Ask customers to check their spam/junk folder
Verify that your confirmation email template is set up correctly
If using Allowed Tags, ensure the customer has the required tag in Shopify
Low confirmation rates
If many subscribers are not confirming:
Review your confirmation email subject line: make it clear and direct
Keep the email design simple with one clear call-to-action
Ensure the confirmation email is sent promptly
Set expectations at sign-up: tell customers to check their inbox
Frequently Asked Questions
Can I switch from single to double opt-in?
Yes, but existing subscribers won't need to re-confirm. DOI only applies to new sign-ups after you enable it.
What if someone never confirms?
They remain in a pending/blocklisted state and cannot receive marketing emails. You can periodically clean up unconfirmed contacts.
Can I customize the confirmation email?
Yes, you can select from available templates on the Opt-in Settings page. To create custom templates, use the Brevo platform.
Does DOI affect SMS subscriptions?
When DOI is enabled, email is collected before SMS to ensure accurate contact merging. SMS subscription handling is separate from the email DOI flow.
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