diff --git a/test/api/unit/middlewares/blocker.test.js b/test/api/unit/middlewares/blocker.test.js
index bd5c5c443f..7e3e167caf 100644
--- a/test/api/unit/middlewares/blocker.test.js
+++ b/test/api/unit/middlewares/blocker.test.js
@@ -29,7 +29,7 @@ function checkErrorNotThrown (next) {
   expect(typeof calledWith[0] === 'undefined').to.equal(true);
 }
 
-describe('Blocker middleware', () => {
+describe.only('Blocker middleware', () => {
   const pathToBlocker = '../../../../website/server/middlewares/blocker';
 
   let res; let req; let next;
diff --git a/test/api/unit/models/user.test.js b/test/api/unit/models/user.test.js
index c5b6054c73..09575a8bf3 100644
--- a/test/api/unit/models/user.test.js
+++ b/test/api/unit/models/user.test.js
@@ -1,9 +1,13 @@
 import moment from 'moment';
+import requireAgain from 'require-again';
 import { model as User } from '../../../../website/server/models/user';
 import { model as NewsPost } from '../../../../website/server/models/newsPost';
 import { model as Group } from '../../../../website/server/models/group';
+import { model as Blocker } from '../../../../website/server/models/blocker';
 import common from '../../../../website/common';
 
+const pathToUserSchema = '../../../../website/server/models/user/schema';
+
 describe('User Model', () => {
   describe('.toJSON()', () => {
     it('keeps user._tmp when calling .toJSON', () => {
@@ -912,4 +916,73 @@ describe('User Model', () => {
       expect(user.toJSON().flags.newStuff).to.equal(true);
     });
   });
+
+  describe.only('validates email', () => {
+    it('does not throw an error for a valid email', () => {
+      const user = new User();
+      user.auth.local.email = 'hello@example.com';
+      const errors = user.validateSync();
+      expect(errors.errors['auth.local.email']).to.not.exist;
+    });
+
+    it('throws an error if email is not valid', () => {
+      const user = new User();
+      user.auth.local.email = 'invalid-email';
+      const errors = user.validateSync();
+      expect(errors.errors['auth.local.email'].message).to.equal(common.i18n.t('invalidEmail'));
+    });
+
+    it('throws an error if email is using a restricted domain', () => {
+      const user = new User();
+      user.auth.local.email = 'scammer@habitica.com';
+      const errors = user.validateSync();
+      expect(errors.errors['auth.local.email'].message).to.equal(common.i18n.t('invalidEmailDomain', { domains: 'habitica.com, habitrpg.com' }));
+    });
+
+    it('throws an error if email was blocked specifically', () => {
+      sandbox.stub(Blocker, 'watchBlockers').returns({
+        on: (event, callback) => {
+          callback({ operation: 'add', blocker: { type: 'email', area: 'full', value: 'blocked@example.com' } });
+        },
+      });
+      const schema = requireAgain(pathToUserSchema).UserSchema;
+      const valid = schema.paths['auth.local.email'].options.validate.every(v => v.validator('blocked@example.com'))
+      expect(valid).to.equal(false);
+    });
+
+    it('throws an error if email domain was blocked', () => {
+      sandbox.stub(Blocker, 'watchBlockers').returns({
+        on: (event, callback) => {
+          callback({ operation: 'add', blocker: { type: 'email', area: 'full', value: '@example.com' } });
+        },
+      });
+      const schema = requireAgain(pathToUserSchema).UserSchema;
+      const valid = schema.paths['auth.local.email'].options.validate.every(v => v.validator('blocked@example.com'));
+      expect(valid).to.equal(false);
+    });
+
+    it('throws an error if user portion of email was blocked', () => {
+      sandbox.stub(Blocker, 'watchBlockers').returns({
+        on: (event, callback) => {
+          callback({ operation: 'add', blocker: { type: 'email', area: 'full', value: 'blocked@' } });
+        },
+      });
+      const schema = requireAgain(pathToUserSchema).UserSchema;
+      const valid = schema.paths['auth.local.email'].options.validate.every(v => v.validator('blocked@example.com'));
+      expect(valid).to.equal(false);
+    });
+
+    it('throws an error if email is not blocked', () => {
+      sandbox.stub(Blocker, 'watchBlockers').returns({
+        on: (event, callback) => {
+          callback({ operation: 'add', blocker: { type: 'email', area: 'full', value: '@example.com' } });
+          callback({ operation: 'add', blocker: { type: 'email', area: 'full', value: 'blocked@' } });
+          callback({ operation: 'add', blocker: { type: 'email', area: 'full', value: 'bad@test.com' } });
+        },
+      });
+      const schema = requireAgain(pathToUserSchema).UserSchema;
+      const valid = schema.paths['auth.local.email'].options.validate.every(v => v.validator('good@test.com'));
+      expect(valid).to.equal(true);
+    });
+  });
 });
diff --git a/website/server/models/user/schema.js b/website/server/models/user/schema.js
index efffc176c0..0277d66de8 100644
--- a/website/server/models/user/schema.js
+++ b/website/server/models/user/schema.js
@@ -9,9 +9,31 @@ import { schema as SubscriptionPlanSchema } from '../subscriptionPlan';
 import { schema as TagSchema } from '../tag';
 import { schema as UserNotificationSchema } from '../userNotification';
 import { schema as WebhookSchema } from '../webhook';
+import { model as Blocker } from '../blocker';
 
 const RESTRICTED_EMAIL_DOMAINS = Object.freeze(['habitica.com', 'habitrpg.com']);
 
+const BLOCKED_EMAILS = [];
+
+Blocker.watchBlockers({
+  type: 'email',
+  area: 'full',
+}, {
+  initial: true,
+}).on('change', async change => {
+  const { operation, blocker: { value } } = change;
+  if (operation === 'add') {
+    if (value && !BLOCKED_EMAILS.includes(value)) {
+      BLOCKED_EMAILS.push(value);
+    }
+  } else if (operation === 'delete') {
+    const index = BLOCKED_EMAILS.indexOf(value);
+    if (index !== -1) {
+      BLOCKED_EMAILS.splice(index, 1);
+    }
+  }
+});
+
 // User schema definition
 export const UserSchema = new Schema({
   apiToken: {
@@ -43,6 +65,12 @@ export const UserSchema = new Schema({
             return RESTRICTED_EMAIL_DOMAINS.every(domain => !lowercaseEmail.endsWith(`@${domain}`));
           },
           message: shared.i18n.t('invalidEmailDomain', { domains: RESTRICTED_EMAIL_DOMAINS.join(', ') }),
+        }, {
+          validator (email) {
+            const lowercaseEmail = email.toLowerCase();
+            return BLOCKED_EMAILS.every(block => lowercaseEmail.indexOf(block) === -1);
+          },
+          message: shared.i18n.t('emailBlockedRegistration'),
         }],
       },
       username: {