Showing the attachment symbol on an email in the list with only inline attachments is confusing

[armhub]

Discussion: When there are only inline attachments on an email and no "normal" attachments we currently show the attachment symbol on the email in the email list. This is confusing because you would expect to see an attachment bubble in the email, especially if these inline attachments are formatting images or signature logos. On the other hand some users put images into emails as inline attachments which they expect to be regarded as "normal" attachments.

Options:

• Do not show the attachment symbol in the list if there are only inline attachments. Another encrypted boolean field would be needed on the mail type.
• Show an inline attachment bubble in the mail, so you understand why there is an attachment symbol as soon as you open the email.

[bedhub]

I would like to discuss this case again because i prefer to keep the attachment symbol in the mail list. We have three cases of attachment right now:

1. regular attachments -> Attachment symbol, Attachment bubble
2. Inline attachments added from the mail editor. (send as attachment and referenced by cid from the mail body) -> Attachment symbol -> No attachment bubble
3. Embedded images from mail signature (send as base64 url) -> No attachment symbol, No attachment bubble

For case 3 (signature images) we need to find another solution as the base64 images are not shown by every webmail provider (e.g. gmail). Best would be to handle them like case 2 (inline attachments referenced by cid) see #1881.