Basic docs for most classes

1 files changed, 9 insertions, 0 deletions

diff --git a/app/models/action_mailbox/inbound_email/message_id.rb b/app/models/action_mailbox/inbound_email/message_id.rb
index 70d39d1e33..dc17e48e74 100644
--- a/app/models/action_mailbox/inbound_email/message_id.rb
+++ b/app/models/action_mailbox/inbound_email/message_id.rb
@@ -1,3 +1,9 @@
+# The `Message-ID` as specified by rfc822 is supposed to be a unique identifier for that individual email. 
+# That makes it an ideal tracking token for debugging and forensics, just like `X-Request-Id` does for 
+# web request.
+#
+# If an inbound email does not, against the rfc822 mandate, specify a Message-ID, one will be generated
+# using the approach from `Mail::MessageIdField`.
 module ActionMailbox::InboundEmail::MessageId
   extend ActiveSupport::Concern
 
@@ -6,6 +12,9 @@ module ActionMailbox::InboundEmail::MessageId
   end
 
   module ClassMethods
+    # Create a new `InboundEmail` from the raw `source` of the email, which be uploaded as a Active Storage
+    # attachment called `raw_email`. Before the upload, extract the Message-ID from the `source` and set
+    # it as an attribute on the new `InboundEmail`.
     def create_and_extract_message_id!(source, **options)
       create! message_id: extract_message_id(source), **options do |inbound_email|
         inbound_email.raw_email.attach io: StringIO.new(source), filename: "message.eml", content_type: "message/rfc822"