diff --git a/app/helpers/api/v1/inboxes_helper.rb b/app/helpers/api/v1/inboxes_helper.rb
index d734a346e..3d6b559c8 100644
--- a/app/helpers/api/v1/inboxes_helper.rb
+++ b/app/helpers/api/v1/inboxes_helper.rb
@@ -57,39 +57,35 @@ module Api::V1::InboxesHelper
   end
 
   def check_smtp_connection(channel_data, smtp)
+    smtp.open_timeout = 10
     smtp.start(channel_data[:smtp_domain], channel_data[:smtp_login], channel_data[:smtp_password],
                channel_data[:smtp_authentication]&.to_sym || :login)
     smtp.finish
+  rescue Net::SMTPAuthenticationError
+    raise StandardError, I18n.t('errors.inboxes.smtp.authentication_error')
+  rescue SocketError, Errno::ECONNREFUSED, Errno::EHOSTUNREACH, Errno::ENETUNREACH, Net::OpenTimeout
+    raise StandardError, I18n.t('errors.inboxes.smtp.connection_error')
+  rescue OpenSSL::SSL::SSLError
+    raise StandardError, I18n.t('errors.inboxes.smtp.ssl_error')
+  rescue Net::SMTPServerBusy, Net::SMTPSyntaxError, Net::SMTPFatalError
+    raise StandardError, I18n.t('errors.inboxes.smtp.smtp_error')
+  rescue StandardError => e
+    raise StandardError, e.message
   end
 
   def set_smtp_encryption(channel_data, smtp)
     if channel_data[:smtp_enable_ssl_tls]
-      set_enable_tls(channel_data, smtp)
+      set_smtp_ssl_method(smtp, :enable_tls, channel_data[:smtp_openssl_verify_mode])
     elsif channel_data[:smtp_enable_starttls_auto]
-      set_enable_starttls_auto(channel_data, smtp)
+      set_smtp_ssl_method(smtp, :enable_starttls_auto, channel_data[:smtp_openssl_verify_mode])
     end
   end
 
-  def set_enable_starttls_auto(channel_data, smtp)
-    return unless smtp.respond_to?(:enable_starttls_auto)
+  def set_smtp_ssl_method(smtp, method, openssl_verify_mode)
+    return unless smtp.respond_to?(method)
 
-    if channel_data[:smtp_openssl_verify_mode]
-      context = enable_openssl_mode(channel_data[:smtp_openssl_verify_mode])
-      smtp.enable_starttls_auto(context)
-    else
-      smtp.enable_starttls_auto
-    end
-  end
-
-  def set_enable_tls(channel_data, smtp)
-    return unless smtp.respond_to?(:enable_tls)
-
-    if channel_data[:smtp_openssl_verify_mode]
-      context = enable_openssl_mode(channel_data[:smtp_openssl_verify_mode])
-      smtp.enable_tls(context)
-    else
-      smtp.enable_tls
-    end
+    context = enable_openssl_mode(openssl_verify_mode) if openssl_verify_mode
+    context ? smtp.send(method, context) : smtp.send(method)
   end
 
   def enable_openssl_mode(smtp_openssl_verify_mode)
diff --git a/app/javascript/dashboard/routes/dashboard/settings/inbox/SmtpSettings.vue b/app/javascript/dashboard/routes/dashboard/settings/inbox/SmtpSettings.vue
index 575e0e5d2..e8bc723c2 100644
--- a/app/javascript/dashboard/routes/dashboard/settings/inbox/SmtpSettings.vue
+++ b/app/javascript/dashboard/routes/dashboard/settings/inbox/SmtpSettings.vue
@@ -147,7 +147,9 @@ export default {
         await this.$store.dispatch('inboxes/updateInboxSMTP', payload);
         useAlert(this.$t('INBOX_MGMT.SMTP.EDIT.SUCCESS_MESSAGE'));
       } catch (error) {
-        useAlert(this.$t('INBOX_MGMT.SMTP.EDIT.ERROR_MESSAGE'));
+        useAlert(
+          error.message || this.$t('INBOX_MGMT.SMTP.EDIT.ERROR_MESSAGE')
+        );
       }
     },
   },
diff --git a/app/services/auto_assignment/rate_limiter.rb b/app/services/auto_assignment/rate_limiter.rb
index da8daac9c..b46148526 100644
--- a/app/services/auto_assignment/rate_limiter.rb
+++ b/app/services/auto_assignment/rate_limiter.rb
@@ -2,8 +2,6 @@ class AutoAssignment::RateLimiter
   pattr_initialize [:inbox!, :agent!]
 
   def within_limit?
-    return true unless enabled?
-
     current_count < limit
   end
 
@@ -13,24 +11,18 @@ class AutoAssignment::RateLimiter
   end
 
   def current_count
-    return 0 unless enabled?
-
     pattern = assignment_key_pattern
     Redis::Alfred.keys_count(pattern)
   end
 
   private
 
-  def enabled?
-    config.present? && limit.positive?
-  end
-
   def limit
-    config&.fair_distribution_limit.present? ? config.fair_distribution_limit.to_i : Float::INFINITY
+    config&.fair_distribution_limit.present? ? config.fair_distribution_limit.to_i : 5
   end
 
   def window
-    config&.fair_distribution_window&.to_i || 24.hours.to_i
+    config&.fair_distribution_window&.to_i || 5.minutes.to_i
   end
 
   def config
diff --git a/config/locales/en.yml b/config/locales/en.yml
index a058d28c7..05276009f 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -108,6 +108,11 @@ en:
         host_unreachable_error: Host unreachable, Please check the IMAP address, IMAP port and try again.
         connection_timed_out_error: Connection timed out for %{address}:%{port}
         connection_closed_error: Connection closed.
+      smtp:
+        authentication_error: SMTP authentication failed. Please verify your login credentials.
+        connection_error: Could not connect to SMTP server. Please check the server address and port.
+        ssl_error: SSL/TLS error. Please verify your encryption settings.
+        smtp_error: SMTP server error. Please check your configuration and try again.
       validations:
         name: should not start or end with symbols, and it should not have < > / \ @ characters.
     custom_filters:
diff --git a/spec/controllers/api/v1/accounts/inboxes_controller_spec.rb b/spec/controllers/api/v1/accounts/inboxes_controller_spec.rb
index fafd6788e..b93ca8ecf 100644
--- a/spec/controllers/api/v1/accounts/inboxes_controller_spec.rb
+++ b/spec/controllers/api/v1/accounts/inboxes_controller_spec.rb
@@ -631,6 +631,7 @@ RSpec.describe 'Inboxes API', type: :request do
 
       it 'updates smtp configuration with starttls encryption' do
         smtp_connection = double
+        allow(smtp_connection).to receive(:open_timeout=).and_return(10)
         allow(smtp_connection).to receive(:start).and_return(true)
         allow(smtp_connection).to receive(:finish).and_return(true)
         allow(smtp_connection).to receive(:respond_to?).and_return(true)
@@ -661,6 +662,7 @@ RSpec.describe 'Inboxes API', type: :request do
 
       it 'updates smtp configuration with ssl/tls encryption' do
         smtp_connection = double
+        allow(smtp_connection).to receive(:open_timeout=).and_return(10)
         allow(smtp_connection).to receive(:start).and_return(true)
         allow(smtp_connection).to receive(:finish).and_return(true)
         allow(smtp_connection).to receive(:respond_to?).and_return(true)
@@ -691,6 +693,7 @@ RSpec.describe 'Inboxes API', type: :request do
 
       it 'updates smtp configuration with authentication mechanism' do
         smtp_connection = double
+        allow(smtp_connection).to receive(:open_timeout=).and_return(10)
         allow(smtp_connection).to receive(:start).and_return(true)
         allow(smtp_connection).to receive(:finish).and_return(true)
         allow(smtp_connection).to receive(:respond_to?).and_return(true)
diff --git a/spec/enterprise/services/enterprise/billing/topup_checkout_service_spec.rb b/spec/enterprise/services/enterprise/billing/topup_checkout_service_spec.rb
index 8a64e6fd2..24c7889de 100644
--- a/spec/enterprise/services/enterprise/billing/topup_checkout_service_spec.rb
+++ b/spec/enterprise/services/enterprise/billing/topup_checkout_service_spec.rb
@@ -44,17 +44,19 @@ describe Enterprise::Billing::TopupCheckoutService do
     end
 
     it 'raises error for invalid credits' do
-      expect do
-        service.create_checkout_session(credits: 500)
-      end.to raise_error(Enterprise::Billing::TopupCheckoutService::Error)
+      expect { service.create_checkout_session(credits: 500) }.to raise_error do |error|
+        expect(error.class.name).to eq('Enterprise::Billing::TopupCheckoutService::Error')
+        expect(error.message).to eq(I18n.t('errors.topup.invalid_option'))
+      end
     end
 
     it 'raises error when account is on free plan' do
       account.update!(custom_attributes: { plan_name: 'Hacker', stripe_customer_id: stripe_customer_id })
 
-      expect do
-        service.create_checkout_session(credits: 1000)
-      end.to raise_error(Enterprise::Billing::TopupCheckoutService::Error)
+      expect { service.create_checkout_session(credits: 1000) }.to raise_error do |error|
+        expect(error.class.name).to eq('Enterprise::Billing::TopupCheckoutService::Error')
+        expect(error.message).to eq(I18n.t('errors.topup.plan_not_eligible'))
+      end
     end
   end
 end
diff --git a/spec/services/auto_assignment/rate_limiter_spec.rb b/spec/services/auto_assignment/rate_limiter_spec.rb
index d5c3de047..59b145c87 100644
--- a/spec/services/auto_assignment/rate_limiter_spec.rb
+++ b/spec/services/auto_assignment/rate_limiter_spec.rb
@@ -61,7 +61,7 @@ RSpec.describe AutoAssignment::RateLimiter do
 
       it 'still tracks the assignment with default window' do
         expected_key = format(Redis::RedisKeys::ASSIGNMENT_KEY, inbox_id: inbox.id, agent_id: agent.id, conversation_id: conversation.id)
-        expect(Redis::Alfred).to receive(:set).with(expected_key, conversation.id.to_s, ex: 24.hours.to_i)
+        expect(Redis::Alfred).to receive(:set).with(expected_key, conversation.id.to_s, ex: 5.minutes.to_i)
         rate_limiter.track_assignment(conversation)
       end
     end
@@ -154,12 +154,12 @@ RSpec.describe AutoAssignment::RateLimiter do
         allow(inbox).to receive(:assignment_policy).and_return(assignment_policy)
       end
 
-      it 'uses the default window value of 24 hours' do
+      it 'uses the default window value of 5 minutes' do
         expected_key = format(Redis::RedisKeys::ASSIGNMENT_KEY, inbox_id: inbox.id, agent_id: agent.id, conversation_id: conversation.id)
         expect(Redis::Alfred).to receive(:set).with(
           expected_key,
           conversation.id.to_s,
-          ex: 86_400
+          ex: 5.minutes.to_i
         )
         rate_limiter.track_assignment(conversation)
       end