diff --git a/spec/jobs/inboxes/fetch_imap_emails_job_spec.rb b/spec/jobs/inboxes/fetch_imap_emails_job_spec.rb
index da4b95b15..1abd7450b 100644
--- a/spec/jobs/inboxes/fetch_imap_emails_job_spec.rb
+++ b/spec/jobs/inboxes/fetch_imap_emails_job_spec.rb
@@ -38,6 +38,14 @@ RSpec.describe Inboxes::FetchImapEmailsJob do
       end
     end
 
+    context 'when channel is in backoff' do
+      it 'does not fetch emails' do
+        allow(imap_email_channel).to receive(:in_backoff?).and_return(true)
+        expect(Imap::FetchEmailService).not_to receive(:new)
+        described_class.perform_now(imap_email_channel)
+      end
+    end
+
     context 'when the channel is regular imap' do
       it 'calls the imap fetch service' do
         fetch_service = double
@@ -56,6 +64,17 @@ RSpec.describe Inboxes::FetchImapEmailsJob do
         described_class.perform_now(imap_email_channel, 4)
         expect(fetch_service).to have_received(:perform)
       end
+
+      it 'clears backoff after successful fetch' do
+        fetch_service = double
+        allow(Imap::FetchEmailService).to receive(:new).and_return(fetch_service)
+        allow(fetch_service).to receive(:perform).and_return([])
+        allow(imap_email_channel).to receive(:clear_backoff!)
+
+        described_class.perform_now(imap_email_channel)
+
+        expect(imap_email_channel).to have_received(:clear_backoff!)
+      end
     end
 
     context 'when the channel is Microsoft' do
@@ -69,6 +88,37 @@ RSpec.describe Inboxes::FetchImapEmailsJob do
       end
     end
 
+    context 'when authentication error is raised' do
+      it 'calls authorization_error! on the channel' do
+        allow(Imap::FetchEmailService).to receive(:new).and_raise(Imap::AuthenticationError)
+        allow(imap_email_channel).to receive(:authorization_error!)
+
+        described_class.perform_now(imap_email_channel)
+
+        expect(imap_email_channel).to have_received(:authorization_error!)
+      end
+    end
+
+    context 'when a transient IMAP error is raised' do
+      it 'calls apply_backoff! on the channel' do
+        allow(Imap::FetchEmailService).to receive(:new).and_raise(EOFError)
+        allow(imap_email_channel).to receive(:apply_backoff!)
+
+        described_class.perform_now(imap_email_channel)
+
+        expect(imap_email_channel).to have_received(:apply_backoff!)
+      end
+    end
+
+    context 'when lock acquisition fails' do
+      it 'does not raise an error' do
+        lock_manager = instance_double(Redis::LockManager, lock: false)
+        allow(Redis::LockManager).to receive(:new).and_return(lock_manager)
+
+        expect { described_class.perform_now(imap_email_channel) }.not_to raise_error
+      end
+    end
+
     context 'when IMAP OAuth errors out' do
       it 'marks the connection as requiring authorization' do
         error_response = double
diff --git a/spec/models/channel/email_spec.rb b/spec/models/channel/email_spec.rb
index 939e8e10a..bdb9f859b 100644
--- a/spec/models/channel/email_spec.rb
+++ b/spec/models/channel/email_spec.rb
@@ -2,12 +2,14 @@
 
 require 'rails_helper'
 require Rails.root.join 'spec/models/concerns/reauthorizable_shared.rb'
+require Rails.root.join 'spec/models/concerns/backoffable_shared.rb'
 
 RSpec.describe Channel::Email do
   let(:channel) { create(:channel_email) }
 
   describe 'concerns' do
     it_behaves_like 'reauthorizable'
+    it_behaves_like 'backoffable'
 
     context 'when prompt_reauthorization!' do
       it 'calls channel notifier mail for email' do
diff --git a/spec/models/concerns/backoffable_shared.rb b/spec/models/concerns/backoffable_shared.rb
new file mode 100644
index 000000000..385f93be7
--- /dev/null
+++ b/spec/models/concerns/backoffable_shared.rb
@@ -0,0 +1,43 @@
+require 'rails_helper'
+
+shared_examples_for 'backoffable' do
+  let(:obj) { FactoryBot.create(described_class.to_s.underscore.tr('/', '_').to_sym) }
+
+  before do
+    allow(GlobalConfigService).to receive(:load).with('BACKOFF_MAX_INTERVAL_MINUTES', 5).and_return(2)
+    allow(GlobalConfigService).to receive(:load).with('BACKOFF_MAX_INTERVAL_COUNT', 10).and_return(3)
+    # max_interval=2, max_retries=(2-1)+3=4; exhausts on 5th apply_backoff!
+  end
+
+  it 'starts with no backoff' do
+    expect(obj.in_backoff?).to be false
+    expect(obj.backoff_retry_count).to eq 0
+  end
+
+  it 'ramps backoff on each failure' do
+    obj.apply_backoff!
+    expect(obj.backoff_retry_count).to eq 1
+    expect(obj.in_backoff?).to be true
+  end
+
+  it 'caps wait time at max interval' do
+    4.times { obj.apply_backoff! }
+    expect(obj.backoff_retry_count).to eq 4
+    expect(obj.in_backoff?).to be true
+  end
+
+  it 'exhausts backoff and calls prompt_reauthorization! after max retries' do
+    allow(obj).to receive(:prompt_reauthorization!)
+    5.times { obj.apply_backoff! }
+    expect(obj).to have_received(:prompt_reauthorization!)
+    expect(obj.backoff_retry_count).to eq 0
+    expect(obj.in_backoff?).to be false
+  end
+
+  it 'clear_backoff! resets retry count and backoff window' do
+    obj.apply_backoff!
+    obj.clear_backoff!
+    expect(obj.in_backoff?).to be false
+    expect(obj.backoff_retry_count).to eq 0
+  end
+end