diff --git a/app/controllers/users/invitations_controller.rb b/app/controllers/users/invitations_controller.rb
index e320a141e..4159df7d6 100644
--- a/app/controllers/users/invitations_controller.rb
+++ b/app/controllers/users/invitations_controller.rb
@@ -14,6 +14,15 @@ module Users
 
     before_action :update_sanitized_params, only: :update
 
+    def new
+      raise NotImplementedError
+    end
+
+    def create
+      # Replaced with invite_users action
+      raise NotImplementedError
+    end
+
     def update
       return super unless Rails.configuration.x.new_team_on_signup
 
@@ -24,11 +33,15 @@ module Users
       super do |user|
         if user.errors.blank?
           @team.created_by = user
-          @team.save
+          @team.save!
         end
       end
     end
 
+    def destroy
+      raise NotImplementedError
+    end
+
     def accept_resource
       return super unless Rails.configuration.x.new_team_on_signup
 
@@ -71,7 +84,7 @@ module Users
           next
         end
         # Check if user already exists
-        user = User.find_by(email: email)
+        user = User.find_by(email: email.downcase)
 
         if user
           result[:status] = :user_exists
@@ -156,6 +169,11 @@ module Users
 
     private
 
+    def invite_resource
+      # Replaced with invite_users action
+      raise NotImplementedError
+    end
+
     def update_sanitized_params
       # Solution for Devise < 4.0.0
       devise_parameter_sanitizer.permit(:accept_invitation, keys: [:full_name])
diff --git a/config/initializers/devise.rb b/config/initializers/devise.rb
index b964cd464..d2c7765a9 100644
--- a/config/initializers/devise.rb
+++ b/config/initializers/devise.rb
@@ -107,7 +107,7 @@ Devise.setup do |config|
   # The period the generated invitation token is valid, after
   # this period, the invited resource won't be able to accept the invitation.
   # When invite_for is 0 (the default), the invitation won't expire.
-  config.invite_for = 7.days
+  # config.invite_for = 7.days
 
   # Number of invitations users can send.
   # - If invitation_limit is nil, there is no limit for invitations, users can
@@ -165,7 +165,7 @@ Devise.setup do |config|
   # their account can't be confirmed with the token any more.
   # Default is nil, meaning there is no restriction on how long a user can take
   # before confirming their account.
-  config.confirm_within = 7.days
+  config.confirm_within = ENV['SCINOTE_USERS_CONFIRM_WITHIN']&.to_i&.days
 
   # If true, requires any email changes to be confirmed (exactly the same way as
   # initial account confirmation) to be applied. Requires additional unconfirmed_email
diff --git a/lib/tasks/data.rake b/lib/tasks/data.rake
index 8caefd19e..141d3a16c 100644
--- a/lib/tasks/data.rake
+++ b/lib/tasks/data.rake
@@ -50,32 +50,36 @@ namespace :data do
     end
   end
 
-  desc "Remove unconfirmed user accounts"
+  desc 'Remove unconfirmed user accounts'
   task clean_unconfirmed_users: :environment do
-    Rails.logger.info "Cleaning unconfirmed users"
+    Rails.logger.info 'Cleaning unconfirmed users'
 
     # First, remove the users who signed up by themselves
-    users = User
-    .where(confirmed_at: nil)
-    .where.not(confirmation_token: nil)
-    .where(invitation_token: nil)
-    .where("created_at < ?", Devise.confirm_within.ago)
-    destroy_users(users)
+    if Devise.confirm_within.present?
+      users = User.where(confirmed_at: nil)
+                  .where.not(confirmation_token: nil)
+                  .where(invitation_token: nil)
+                  .where(created_at: ...Devise.confirm_within.ago)
+      destroy_users(users)
+    end
 
     # Now, remove users who were invited
-    users = User
-    .where(confirmed_at: nil)
-    .where(invitation_accepted_at: nil)
-    .where(confirmation_token: nil)
-    .where.not(invitation_token: nil)
-    .where("created_at < ?", Devise.invite_for.ago)
-    destroy_users(users)
+    unless Devise.invite_for.zero?
+      users = User.where(confirmed_at: nil)
+                  .where(invitation_accepted_at: nil)
+                  .where(confirmation_token: nil)
+                  .where.not(invitation_token: nil)
+                  .where(created_at: ...Devise.invite_for.ago)
+      destroy_users(users)
+    end
 
     # Remove users who didn't finish signup with LinkedIn
-    users = User.joins(:user_identities)
-                .where(confirmed_at: nil)
-                .where('users.created_at < ?', Devise.confirm_within.ago)
-    destroy_users(users)
+    if Devise.confirm_within.present?
+      users = User.joins(:user_identities)
+                  .where(confirmed_at: nil)
+                  .where(users: { created_at: ...Devise.confirm_within.ago })
+      destroy_users(users)
+    end
   end
 
   desc "Remove temporary and obsolete data"