It turns out to be quite easy to send emails with .NET that use embedded images. By embedding I mean actually include the image as an MIME attachment.
I'm just trying to figure out whether or not I should embed images as resources for mass mailings (to opt-in / existing customers). Alternatively I would just reference images with a <img src>
Reasons for embedding images
- Spam filters may be less likely to block emails - because no tracking pixels exist
- Email clients may be more likely to show the images - because no tracking pixels exist
- Available for offline viewing
- We don't need to host the images indefinitely
Reasons for not embedding images (IMG src attribute pointing to an external site)
- Spam filters may be more likely to block large files if we have lots of images
- We get to host the images and change them if we made a mistake
- We can track views of emails in server logs
- Blasting out a tonne of emails should take a lot less time
- We take less of a server bandwidth hit for the hosted images555
- Sending out many emails with embedded images may take a long time becuse we have to send 400kb for each email
I'm sure there are more reasons.
I'm most concerned about spam related issues. Curious for anybody's input