diff --git a/README.md b/README.md
index 9fc392287..dba2f4c3d 100644
--- a/README.md
+++ b/README.md
@@ -67,7 +67,7 @@ You need to make sure those timestamps are always the same across executions.
 
 #### Development
 
-You can view email previews at http://know-it-all.localhost:3005/rails/mailers.
+You can view email previews at http://fizzy.localhost:3006/rails/mailers.
 
 You can enable or disable [`letter_opener`](https://github.com/ryanb/letter_opener) to
 open sent emails automatically with:
diff --git a/app/jobs/notification/bundle/deliver_all_job.rb b/app/jobs/notification/bundle/deliver_all_job.rb
new file mode 100644
index 000000000..cdd6093ce
--- /dev/null
+++ b/app/jobs/notification/bundle/deliver_all_job.rb
@@ -0,0 +1,5 @@
+class Notification::Bundle::DeliverAllJob < ApplicationJob
+  def perform
+    Notification::Bundle.deliver_all
+  end
+end
diff --git a/app/jobs/notification/bundle/deliver_job.rb b/app/jobs/notification/bundle/deliver_job.rb
new file mode 100644
index 000000000..b4c64a6c2
--- /dev/null
+++ b/app/jobs/notification/bundle/deliver_job.rb
@@ -0,0 +1,5 @@
+class Notification::Bundle::DeliverJob < ApplicationJob
+  def perform(bundle)
+    bundle.deliver
+  end
+end
diff --git a/app/mailers/notification/bundle_mailer.rb b/app/mailers/notification/bundle_mailer.rb
new file mode 100644
index 000000000..a3e830b16
--- /dev/null
+++ b/app/mailers/notification/bundle_mailer.rb
@@ -0,0 +1,11 @@
+class Notification::BundleMailer < ApplicationMailer
+  def notification(bundle)
+    @bundle = bundle
+    @notifications = bundle.notifications
+    
+    mail(
+      to: bundle.user.email_address,
+      subject: "You have #{@notifications.count} notifications"
+    )
+  end
+end
\ No newline at end of file
diff --git a/app/models/notification.rb b/app/models/notification.rb
index 943cafd7e..0b1e2e377 100644
--- a/app/models/notification.rb
+++ b/app/models/notification.rb
@@ -10,6 +10,7 @@ class Notification < ApplicationRecord
   scope :ordered, -> { order(read_at: :desc, created_at: :desc) }
 
   after_create_commit :broadcast_unread
+  after_create :bundle
 
   delegate :notifiable_target, to: :source
   delegate :card, to: :source
@@ -40,4 +41,8 @@ class Notification < ApplicationRecord
     def broadcast_read
       broadcast_remove_to user, :notifications
     end
+
+    def bundle
+      user.bundle(self)
+    end
 end
diff --git a/app/models/notification/bundle.rb b/app/models/notification/bundle.rb
new file mode 100644
index 000000000..31b16ac7e
--- /dev/null
+++ b/app/models/notification/bundle.rb
@@ -0,0 +1,51 @@
+class Notification::Bundle < ApplicationRecord
+  belongs_to :user
+
+  enum :status, %i[ pending processing delivered ]
+
+  before_create :set_default_window
+
+  scope :due, -> { pending.where("ends_at <= ?", Time.current) }
+
+  class << self
+    def deliver_all
+      due.in_batches do |batch|
+        DeliverJob.perform_all_later batch
+      end
+    end
+
+    def deliver_all_later
+      DeliverAllJob.perform_later
+    end
+  end
+
+  def add(notification)
+    update! ends_at: [ ends_at, notification.created_at ].max
+  end
+
+  def notifications
+    user.notifications.where(created_at: window)
+  end
+
+  def deliver
+    processing!
+    BundleMailer.notification(self).deliver
+    delivered!
+  end
+
+  def deliver_later
+    DeliverJob.perform_later(self)
+  end
+
+  private
+    AGGREGATION_PERIOD = 4.hours
+
+    def set_default_window
+      self.starts_at ||= Time.current
+      self.ends_at ||= AGGREGATION_PERIOD.from_now
+    end
+
+    def window
+      starts_at..ends_at
+    end
+end
diff --git a/app/models/user.rb b/app/models/user.rb
index bd8cf990d..21007d711 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -1,5 +1,5 @@
 class User < ApplicationRecord
-  include Accessor, Attachable, Assignee, Mentionable, Named, Role, Searcher,
+  include Accessor, Attachable, Assignee, Mentionable, Named, Notifiable, Role, Searcher,
     SignalUser, Staff, Transferable, Conversational
   include Timelined # Depends on Accessor
 
@@ -10,8 +10,6 @@ class User < ApplicationRecord
 
   has_many :comments, inverse_of: :creator, dependent: :destroy
 
-  has_many :notifications, dependent: :destroy
-
   has_many :filters, foreign_key: :creator_id, inverse_of: :creator, dependent: :destroy
   has_many :closures, dependent: :nullify
   has_many :pins, dependent: :destroy
diff --git a/app/models/user/notifiable.rb b/app/models/user/notifiable.rb
new file mode 100644
index 000000000..0f6cf3b94
--- /dev/null
+++ b/app/models/user/notifiable.rb
@@ -0,0 +1,19 @@
+module User::Notifiable
+  extend ActiveSupport::Concern
+
+  included do
+    has_many :notifications, dependent: :destroy
+    has_many :notification_bundles, class_name: "Notification::Bundle", dependent: :destroy
+  end
+
+  def bundle(notification)
+    transaction do
+      find_or_create_pending_bundle_for(notification).add(notification)
+    end
+  end
+
+  private
+    def find_or_create_pending_bundle_for(notification)
+      notification_bundles.pending.last || notification_bundles.create!(starts_at: notification.created_at)
+    end
+end
diff --git a/app/views/notification/bundle_mailer/notification.html.erb b/app/views/notification/bundle_mailer/notification.html.erb
new file mode 100644
index 000000000..1fd9371f0
--- /dev/null
+++ b/app/views/notification/bundle_mailer/notification.html.erb
@@ -0,0 +1,9 @@
+<h2>Your Notifications</h2>
+
+<p>You have <%= @notifications.count %> notifications:</p>
+
+<ul>
+  <% @notifications.each do |notification| %>
+    <li>Notification ID: <%= notification.id %></li>
+  <% end %>
+</ul>
\ No newline at end of file
diff --git a/app/views/notification/bundle_mailer/notification.text.erb b/app/views/notification/bundle_mailer/notification.text.erb
new file mode 100644
index 000000000..8b7c8f424
--- /dev/null
+++ b/app/views/notification/bundle_mailer/notification.text.erb
@@ -0,0 +1 @@
+PENDING...
diff --git a/config/recurring.yml b/config/recurring.yml
index 99b3c1f33..66188ec7a 100644
--- a/config/recurring.yml
+++ b/config/recurring.yml
@@ -17,6 +17,9 @@ production: &production
   clear_solid_queue_finished_jobs:
     command: "SolidQueue::Job.clear_finished_in_batches(sleep_between_batches: 0.3)"
     schedule: every hour at minute 12
+  deliver_bundled_notifications:
+    command: "Notification::Bundle.deliver_all_later"
+    schedule: every 30 minutes
 
 beta: *production
 staging: *production
diff --git a/db/migrate/20250826084559_create_notification_bundles.rb b/db/migrate/20250826084559_create_notification_bundles.rb
new file mode 100644
index 000000000..5c3f3ebfb
--- /dev/null
+++ b/db/migrate/20250826084559_create_notification_bundles.rb
@@ -0,0 +1,15 @@
+class CreateNotificationBundles < ActiveRecord::Migration[8.1]
+  def change
+    create_table :notification_bundles do |t|
+      t.references :user, null: false, foreign_key: true, index: { unique: true }
+      t.datetime :starts_at, null: false
+      t.datetime :ends_at, null: false
+      t.integer :status, default: 0, null: false
+
+      t.timestamps
+    end
+
+    add_index :notification_bundles, %i[ user_id starts_at ends_at ]
+    add_index :notification_bundles, %i[ user_id status ]
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index b31a7dc51..c27e4b231 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.1].define(version: 2025_08_19_105245) do
+ActiveRecord::Schema[8.1].define(version: 2025_08_26_084559) do
   create_table "accesses", force: :cascade do |t|
     t.datetime "accessed_at"
     t.integer "collection_id", null: false
@@ -295,6 +295,18 @@ ActiveRecord::Schema[8.1].define(version: 2025_08_19_105245) do
     t.index ["source_type", "source_id"], name: "index_mentions_on_source"
   end
 
+  create_table "notification_bundles", force: :cascade do |t|
+    t.datetime "created_at", null: false
+    t.datetime "ends_at", null: false
+    t.datetime "starts_at", null: false
+    t.integer "status", default: 0, null: false
+    t.datetime "updated_at", null: false
+    t.integer "user_id", null: false
+    t.index ["user_id", "starts_at", "ends_at"], name: "idx_on_user_id_starts_at_ends_at_7eae5d3ac5"
+    t.index ["user_id", "status"], name: "index_notification_bundles_on_user_id_and_status"
+    t.index ["user_id"], name: "index_notification_bundles_on_user_id", unique: true
+  end
+
   create_table "notifications", force: :cascade do |t|
     t.datetime "created_at", null: false
     t.integer "creator_id"
@@ -451,6 +463,7 @@ ActiveRecord::Schema[8.1].define(version: 2025_08_19_105245) do
   add_foreign_key "events", "collections"
   add_foreign_key "mentions", "users", column: "mentionee_id"
   add_foreign_key "mentions", "users", column: "mentioner_id"
+  add_foreign_key "notification_bundles", "users"
   add_foreign_key "notifications", "users"
   add_foreign_key "notifications", "users", column: "creator_id"
   add_foreign_key "pins", "cards"
diff --git a/db/schema_cache.yml b/db/schema_cache.yml
index 58f3518f3..811f78807 100644
--- a/db/schema_cache.yml
+++ b/db/schema_cache.yml
@@ -909,6 +909,41 @@ columns:
     collation:
     comment:
   - *9
+  notification_bundles:
+  - *5
+  - !ruby/object:ActiveRecord::ConnectionAdapters::SQLite3::Column
+    auto_increment:
+    name: ends_at
+    cast_type: *1
+    sql_type_metadata: *2
+    'null': false
+    default:
+    default_function:
+    collation:
+    comment:
+  - *6
+  - !ruby/object:ActiveRecord::ConnectionAdapters::SQLite3::Column
+    auto_increment:
+    name: starts_at
+    cast_type: *1
+    sql_type_metadata: *2
+    'null': false
+    default:
+    default_function:
+    collation:
+    comment:
+  - !ruby/object:ActiveRecord::ConnectionAdapters::SQLite3::Column
+    auto_increment:
+    name: status
+    cast_type: *3
+    sql_type_metadata: *4
+    'null': false
+    default: 0
+    default_function:
+    collation:
+    comment:
+  - *9
+  - *25
   notifications:
   - *5
   - !ruby/object:ActiveRecord::ConnectionAdapters::SQLite3::Column
@@ -1284,6 +1319,7 @@ primary_keys:
   filters_stages:
   filters_tags:
   mentions: id
+  notification_bundles: id
   notifications: id
   pins: id
   push_subscriptions: id
@@ -1332,6 +1368,7 @@ data_sources:
   filters_stages: true
   filters_tags: true
   mentions: true
+  notification_bundles: true
   notifications: true
   pins: true
   push_subscriptions: true
@@ -2294,6 +2331,58 @@ indexes:
     nulls_not_distinct:
     comment:
     valid: true
+  notification_bundles:
+  - !ruby/object:ActiveRecord::ConnectionAdapters::IndexDefinition
+    table: notification_bundles
+    name: idx_on_user_id_starts_at_ends_at_7eae5d3ac5
+    unique: false
+    columns:
+    - user_id
+    - starts_at
+    - ends_at
+    lengths: {}
+    orders: {}
+    opclasses: {}
+    where:
+    type:
+    using:
+    include:
+    nulls_not_distinct:
+    comment:
+    valid: true
+  - !ruby/object:ActiveRecord::ConnectionAdapters::IndexDefinition
+    table: notification_bundles
+    name: index_notification_bundles_on_user_id
+    unique: true
+    columns:
+    - user_id
+    lengths: {}
+    orders: {}
+    opclasses: {}
+    where:
+    type:
+    using:
+    include:
+    nulls_not_distinct:
+    comment:
+    valid: true
+  - !ruby/object:ActiveRecord::ConnectionAdapters::IndexDefinition
+    table: notification_bundles
+    name: index_notification_bundles_on_user_id_and_status
+    unique: false
+    columns:
+    - user_id
+    - status
+    lengths: {}
+    orders: {}
+    opclasses: {}
+    where:
+    type:
+    using:
+    include:
+    nulls_not_distinct:
+    comment:
+    valid: true
   notifications:
   - !ruby/object:ActiveRecord::ConnectionAdapters::IndexDefinition
     table: notifications
@@ -2771,4 +2860,4 @@ indexes:
     comment:
     valid: true
   workflows: []
-version: 20250819105245
+version: 20250826084559
diff --git a/test/mailers/previews/notification/bundle_mailer_preview.rb b/test/mailers/previews/notification/bundle_mailer_preview.rb
new file mode 100644
index 000000000..3c279e916
--- /dev/null
+++ b/test/mailers/previews/notification/bundle_mailer_preview.rb
@@ -0,0 +1,6 @@
+class Notification::BundleMailerPreview < ActionMailer::Preview
+  def notification
+    ApplicationRecord.current_tenant = "1065895976"
+    Notification::BundleMailer.notification Notification::Bundle.take!
+  end
+end
diff --git a/test/models/notification/bundle_test.rb b/test/models/notification/bundle_test.rb
new file mode 100644
index 000000000..1033a46a7
--- /dev/null
+++ b/test/models/notification/bundle_test.rb
@@ -0,0 +1,35 @@
+require "test_helper"
+
+class Notification::BundleTest < ActiveSupport::TestCase
+  setup do
+    @user = users(:david)
+  end
+
+  test "new notifications are bundled" do
+    notification = assert_difference -> { @user.notification_bundles.pending.count }, 1 do
+      @user.notifications.create!(source: events(:logo_published), creator: @user)
+    end
+
+    bundle = @user.notification_bundles.pending.last
+    assert_includes bundle.notifications, notification
+  end
+
+  test "notifications are bundled withing the aggregation period" do
+    notification_1 = assert_difference -> { @user.notification_bundles.pending.count }, 1 do
+      @user.notifications.create!(source: events(:logo_published), creator: @user)
+    end
+    travel_to 3.hours.from_now
+
+    notification_2 = assert_no_difference -> { @user.notification_bundles.count } do
+      @user.notifications.create!(source: events(:logo_published), creator: @user)
+    end
+    travel_to 3.hours.from_now
+
+    notification_3 = assert_difference -> { @user.notification_bundles.pending.count }, 1 do
+      @user.notifications.create!(source: events(:logo_published), creator: @user)
+    end
+
+    bundle_1, bundle_2 = @user.notification_bundles.last(2)
+
+  end
+end