Add support for configurable dequeue size

app/lib/message_dequeuer/initial_processor.rb

@@ -57,7 +57,7 @@ def check_message_is_ready
     def find_other_messages_for_batch
       return unless Postal::Config.postal.batch_queued_messages?
 
-      @other_messages = @queued_message.batchable_messages(100)
+      @other_messages = @queued_message.batchable_messages(Postal::Config.postal.batch_queued_messages_limit)
       log "found #{@other_messages.size} associated messages to process at the same time", batch_key: @queued_message.batch_key
     rescue StandardError
       @queued_message.unlock

doc/config/yaml.yml

@@ -33,6 +33,8 @@ postal:
   queued_message_lock_stale_days: 1
   # When enabled queued messages will be de-queued in batches based on their destination
   batch_queued_messages: true
+  # When de-queuing in batches, use this limit for the batch size
+  batch_queued_messages_limit: 100
 
 web_server:
   # The default port the web server should listen on unless overriden by the PORT environment variable

lib/postal/config_schema.rb

@@ -101,6 +101,11 @@ module Postal
         description "When enabled queued messages will be de-queued in batches based on their destination"
         default true
       end
+
+      integer :batch_queued_messages_limit do
+        description "When de-queuing in batches, use this limit for the batch size"
+        default 100
+      end
     end
 
     group :web_server do