Your suggestion seems better than mine.

Personally I don't work with business cards in the same sense that I work with documents, and I don't consider an html version an attachment in a work context. So I was just imagining the visual comfort of this:

Currently, in messages lists windows, there is a column for attachments, and a number of other icons can be displayed there too.

In my use, it is not useful, at that stage, to know whether the message contains an HTML version, a business card, or else. On the contrary, I would greatly benefit if that column could display the attachments only.

Visually, a mixture of Attachments icons and blank otherwise would be direct to the point in my professional use.

I agree that there needs to be a column solely for the marking of messages with attachments. However, I do not feel that the current column should be removed. There may be an argument for taking off the default list of columns.

Which leads to a bigger discussion - should there not be an editable selection of info columns? Most other clients have this facility and I certainly use it in the mailer I'm forced to use at work. Users should be able to select which details are presented in the list of messages and also the order in which the columns are displayed.