mail-embed-html-images

Extends Mail to provide a mechanism for converting external image sources to embedded attachments.

require 'mail'
require 'mail/embed-html-images'

mail = Mail.new do
  from       'sender@example.com'
  to         'recipient@example.com''
  subject    'This is a test email'
  html_part  File.read('body.html')
end

mail.embed_html_images
mail.deliver

The embed_html_images method looks for image tags with http[s] sources, downloads the image from the src attribute, adds it as an attachment, and replaces the original src attribute with a cid reference to the attachment.

It keeps track of downloaded files so if you have two images with the same source it will only download and attach tha image once and ref the same attachment from both images.

If you change the html_part, then you will need to re-run embed_html_images. This will download any new images found, and remove any attached images which are no longer required.

That is all.