Correctly Formatting Aggregate Email Messages
What a headache.
In an earlier post I mentioned some crucial documentation I had been missing. Since then I found another fundamental RFC addressing similar issues in formatting emails with embedded images or other objects in addition to a plain text or HTML message.
Here they are:
RFC 2392 - Content-ID and Message-ID Uniform Resource Locators
RFC 2557 - MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)
If you want to ship, and refer to, image files or otherwise along with your email messages in your application, keep these resources in mind. I found I was hanging the Mail::Sendmail module when I wasn’t formatting the messages correctly, especially in regards to the “boundaries” betwixt message parts. Details count. Since I wasn’t even receiving the emails at all to debug, I had to dump the message bodies into a text file to see what was the matter. No joy for me today.