User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:65.0) Gecko/20100101 Firefox/65.0

Steps to reproduce:

I send a mail with a attachment and a digital signature.

Actual results:

Sending mail is successful, but in the message list for the folder "sent mails" there is no attachment icon for this message. Its showed only after the message was opened.

Expected results:

In the message list for the folder "sent mails" the attachment icon should shown for each message with a attachment.

(The bug prevent searching and filtering for messages with attachments.)

Yes, confirmed. Kai, any cycles for something like this?

Try the AttachmentCount extension. Encrypted parts are handled and the flag is always set without message selection required, for immediate filtering/searching.

Maybe someone else could look into this bug and figure what's necessary to fix it. The description text for the extension mentioned in comment 2 says the message needs to be downloaded prior to showing the icon? Do you really want that to be done automatically? If it works for other messages, how is the icon set without downloading it first?