diff --git a/app/views/submitter_mailer/invitation_email.html.erb b/app/views/submitter_mailer/invitation_email.html.erb
index 98f71906..5dfaad26 100644
--- a/app/views/submitter_mailer/invitation_email.html.erb
+++ b/app/views/submitter_mailer/invitation_email.html.erb
@@ -1,7 +1,7 @@
 <% if @email_config || @body.present? %>
   <% body = (@body.presence || @email_config.value['body']).to_s %>
   <%= render 'custom_content', content: body, submitter: @submitter %>
-  <% if !body.include?(ReplaceEmailVariables::SUBMITTER_LINK) && !body.include?(ReplaceEmailVariables::SUBMITTER_ID) && !body.include?(ReplaceEmailVariables::SUBMISSION_LINK) && !body.include?(ReplaceEmailVariables::TEMPLATE_ID) && !@submitter.submission.source.in?(%w[api embed]) %>
+  <% if !body.match?(ReplaceEmailVariables::SUBMITTER_LINK) && !body.match?(ReplaceEmailVariables::SUBMITTER_ID) && !body.match?(ReplaceEmailVariables::SUBMISSION_LINK) && !body.match?(ReplaceEmailVariables::TEMPLATE_ID) && !@submitter.submission.source.in?(%w[api embed]) %>
     <p><%= link_to nil, submit_form_url(slug: @submitter.slug, t: SubmissionEvents.build_tracking_param(@submitter, 'click_email')) %></p>
   <% end %>
 <% else %>
diff --git a/lib/replace_email_variables.rb b/lib/replace_email_variables.rb
index 0d158887..c35b7bc9 100644
--- a/lib/replace_email_variables.rb
+++ b/lib/replace_email_variables.rb
@@ -1,21 +1,21 @@
 # frozen_string_literal: true
 
 module ReplaceEmailVariables
-  TEMPLATE_NAME = '{{template.name}}'
-  TEMPLATE_ID = '{{template.id}}'
-  SUBMITTER_LINK = '{{submitter.link}}'
-  ACCOUNT_NAME = '{{account.name}}'
-  SENDER_NAME = '{{sender.name}}'
-  SENDER_EMAIL = '{{sender.email}}'
-  SUBMITTER_EMAIL = '{{submitter.email}}'
-  SUBMITTER_NAME = '{{submitter.name}}'
-  SUBMITTER_ID = '{{submitter.id}}'
-  SUBMITTER_SLUG = '{{submitter.slug}}'
-  SUBMISSION_LINK = '{{submission.link}}'
-  SUBMISSION_ID = '{{submission.id}}'
-  SUBMISSION_SUBMITTERS = '{{submission.submitters}}'
-  DOCUMENTS_LINKS = '{{documents.links}}'
-  DOCUMENTS_LINK = '{{documents.link}}'
+  TEMPLATE_NAME = /\{+template\.name\}+/i
+  TEMPLATE_ID = /\{+template\.id\}+/i
+  SUBMITTER_LINK = /\{+submitter\.link\}+/i
+  ACCOUNT_NAME = /\{+account\.name\}+/i
+  SENDER_NAME = /\{+sender\.name\}+/i
+  SENDER_EMAIL = /\{+sender\.email\}+/i
+  SUBMITTER_EMAIL = /\{+submitter\.email\}+/i
+  SUBMITTER_NAME = /\{+submitter\.name\}+/i
+  SUBMITTER_ID = /\{+submitter\.id\}+/i
+  SUBMITTER_SLUG = /\{+submitter\.slug\}+/i
+  SUBMISSION_LINK = /\{+submission\.link\}+/i
+  SUBMISSION_ID = /\{+submission\.id\}+/i
+  SUBMISSION_SUBMITTERS = /\{+submission\.submitters\}+/i
+  DOCUMENTS_LINKS = /\{+documents\.links\}+/i
+  DOCUMENTS_LINK = /\{+documents\.link\}+/i
 
   module_function