Using the OS X 10.8.3 Mail.app client, the email notifications in 5.2-beta1 are broken as they relate to file attachments.

To reproduce, I went to an existing page, went into the editor, clicked "+" -> Attachment, and used the Browse link to upload a local file. After the upload completed, the email was delivered to my inbox looking as shown in the attachment. The email source is also attached as emailbody.txt.

Specific issues:

1- There is a big "Missing plug-in" square in the middle of the screen. It looks like it's coming from this:

<img class="icon" src="cid:attachment-icon" alt="" />

(There appears to be no corresponding "attachment-icon" image in the mail.)

2- The RHS margin of the email body is clipped. Notice how the "Manage notification" is flush right with the window border (no matter how large I make the window), and that there is shaded gray LHS margin but no RHS margin.