diff --git a/app/mailers/request_mailer.rb b/app/mailers/request_mailer.rb
index bf8b417342..034694c345 100644
--- a/app/mailers/request_mailer.rb
+++ b/app/mailers/request_mailer.rb
@@ -251,48 +251,61 @@ def requests_matching_email(email)
     InfoRequest.matching_incoming_email(addresses.uniq)
   end
 
+  def send_to_holding_pen(email, raw_email, opts)
+    opts[:rejected_reason] =
+    _("Could not identify the request from the email address")
+    request = InfoRequest.holding_pen_request
+    request.receive(email, raw_email, opts)
+  end
+
   # Member function, called on the new class made in self.receive above
   def receive(email, raw_email, source = :mailin)
     opts = { source: source }
+    # Only check mail that doesn't have spam in the header
+    unless SpamAddress.spam?(MailHandler.get_all_addresses(email))
+      used_guesses = false
+      # Find exact matches for info requests
+      reply_info_requests = requests_matching_email(email)
 
-    # Find which info requests the email is for
-    reply_info_requests = requests_matching_email(email)
-
-    # Nothing found OR multiple different info requests, so a candidate for the
-    # holding pen
-    if reply_info_requests.empty? || reply_info_requests.count > 1
-      # Guess which requests this COULD be related to
+      # Find any guesses for info requests
       guessed_info_requests = guess_email_request_address(email)
-      # If only one request is guessed, then this is should be automatically
-      # attached to that request
-      if guessed_info_requests.count == 1
-        guessed_info_requests.first.log_event(
-          'redeliver_incoming',
-          editor: 'automatic',
-          destination_request: guessed_info_requests.first,
-        )
-      else
-        opts[:rejected_reason] =
-          _("Could not identify the request from the email address")
-        request = InfoRequest.holding_pen_request
-
-        unless SpamAddress.spam?(MailHandler.get_all_addresses(email))
-          request.receive(email, raw_email, opts)
+      # If there are any guesses which aren't already in the reply_info_requests
+      # then add them, and set the 'used_guesses' flag to true for event logging
+      guessed_info_requests.each do |guess|
+        unless reply_info_requests.include?(guess)
+          reply_info_requests.append(guess)
+          used_guesses = true
         end
-        return # TODO: Check structure of if/else
       end
-    end
 
-    # Send the message to each request, to be archived with it
-    reply_info_requests.each do |reply_info_request|
-      # If environment variable STOP_DUPLICATES is set, don't send message with same id again
-      if ENV['STOP_DUPLICATES']
-        if reply_info_request.already_received?(email, raw_email)
-          raise "message #{ email.message_id } already received by request"
+      # If there is only one info request matching mail, it gets attached to the
+      # request to be archived with it
+      if reply_info_requests.count == 1 and guessed_info_requests.count < 2
+        reply_info_request = reply_info_requests.first
+
+        # If environment variable STOP_DUPLICATES is set, don't send message
+        # with same id again
+        if ENV['STOP_DUPLICATES']
+          if reply_info_request.already_received?(email, raw_email)
+            raise "message #{ email.message_id } already received by request"
+          end
+        end
+
+        if used_guesses
+          reply_info_request.log_event(
+            'redeliver_incoming',
+            editor: 'automatic',
+            destination_request: reply_info_request,
+          )
         end
-      end
 
-      reply_info_request.receive(email, raw_email, opts)
+        reply_info_request.receive(email, raw_email, opts)
+
+      else
+        # Otherwise, if there are no matching IRs, multiple IRs, or multiple IR
+        # guesses, we send the mail to the holding pen
+        send_to_holding_pen(email, raw_email, opts)
+      end
     end
   end