adjust for custom domain

lib/replace_email_variables.rb

@@ -89,8 +89,10 @@ module ReplaceEmailVariables
   # rubocop:enable Metrics
 
   def build_documents_links_text(submitter, sig = nil)
+    url_options = build_url_options_for(submitter)
+
     Rails.application.routes.url_helpers.submissions_preview_url(
-      submitter.submission.slug, { sig:, **Docuseal.default_url_options }.compact
+      submitter.submission.slug, { sig:, **url_options }.compact
     )
   end
 
@@ -139,14 +141,9 @@ module ReplaceEmailVariables
   end
 
   def build_submitter_link(submitter, tracking_event_type)
-    if tracking_event_type == 'click_email'
-      url_options =
-        if EMAIL_HOST.present?
-          { host: EMAIL_HOST, protocol: ENV['FORCE_SSL'].present? ? 'https' : 'http' }
-        else
-          Docuseal.default_url_options
-        end
+    url_options = build_url_options_for(submitter, is_email: tracking_event_type == 'click_email')
 
+    if tracking_event_type == 'click_email'
       Rails.application.routes.url_helpers.submit_form_url(
         slug: submitter.slug,
         t: SubmissionEvents.build_tracking_param(submitter, 'click_email'),
@@ -156,11 +153,22 @@ module ReplaceEmailVariables
       Rails.application.routes.url_helpers.submit_form_url(
         slug: submitter.slug,
         c: SubmissionEvents.build_tracking_param(submitter, 'click_sms'),
-        **Docuseal.default_url_options
+        **url_options
       )
     end
   end
 
+  def build_url_options_for(submitter, is_email: true)
+    if Docuseal.multitenant? &&
+       (config = AccountConfig.find_by(account_id: submitter.account_id, key: :custom_domain))
+      { host: config.value, protocol: 'https' }
+    elsif is_email && EMAIL_HOST.present?
+      { host: EMAIL_HOST, protocol: ENV['FORCE_SSL'].present? ? 'https' : 'http' }
+    else
+      Docuseal.default_url_options
+    end
+  end
+
   def build_submission_link(submission)
     Rails.application.routes.url_helpers.submission_url(submission, **Docuseal.default_url_options)
   end