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Documentation Index

Fetch the complete documentation index at: https://docs.yuko.so/llms.txt

Use this file to discover all available pages before exploring further.

Where to find this: Shopify admin → Apps → Yuko Loyalty → Account → Email Blacklist

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Introduction

The Email Blacklist is a list of email domains (or specific addresses) that should be excluded from earning rewards. The most common use is blocking disposable / temporary email services that fraudsters use to abuse referral programs.

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What problem this solves

Referral fraud almost always uses temporary email services — a fraudster signs up for a hundred accounts via Mailinator and rinses the friend reward. Blocking those domains kills 90% of fraud at the source.

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When to use

  • Before launching the referral program.
  • When you spot fraudulent referral activity.
  • When onboarding to a new market with known fraud patterns.

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Overview

  • Domain-level or address-level blacklist.
  • Applied at customer signup and at referral attribution.
  • Common defaults pre-loaded.
  • Editable at any time.

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Setup

1

Open Email Blacklist

Go to Apps → Yuko Loyalty → Account → Email Blacklist.
2

Review the default list

Yuko ships with a curated list of well-known disposable-email domains.
3

Add domains or addresses

Enter one entry per line:
  • Domain: mailinator.com
  • Address: bad-actor@example.com
4

Save

The list applies immediately to new signups and referrals.

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How it works

  • At customer creation: if the email matches a blacklist entry, the customer is created but won’t earn loyalty rewards.
  • At referral attribution: if the friend’s email matches a blacklist entry, the referral is rejected.
  • The blacklist applies prospectively — customers already created keep their existing data.

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Best practices

Keep the default list and add to it as you spot specific abuse domains.
Don’t blacklist legitimate ESPs like Gmail or Outlook — you’ll exclude real customers.
Pair with Referrals → Program Setup → Fraud prevention for layered fraud controls.

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FAQs

Yes — add the full address (e.g., bad-actor@gmail.com) instead of the domain.
Search community-maintained lists (e.g., disposable-email-domains on GitHub). Your support team will also surface common offenders.

General

Store name, currency, timezone and core preferences.

Platforms

Connected commerce platforms and multi-store setup.

Email Blacklist

Block disposable email domains and known fraud sources.

Book a Free Setup Call

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Contact Support

Visit our support hub for help articles, live chat and ticket submission.

Browse the Guides

Documentation across loyalty, referrals, memberships and more.

Install Yuko

Add Yuko to your Shopify store from the Shopify App Store.