[otrs] Notification Event create e-mail with attachment

Hi I have set up a notification event to notify customers whenever an agent/owner adds an external note to a ticket. However, when the mail is delivered (at least to my MS Outlook 2007 client), the mail has the text as expected, but also an attachment with the HTML code of the message. The attached HTML code seems to be well formed. I would like to know how I can prevent the attachment and just have the text. Create Notification even with following criteria: Name: “Notify of External Note” Recipient: “Customer” Event: “ArticleCreate” State: “open” Article Type: “note-external” Subject : “An agent added a note to your ticket Text: “ wrote: \n\n” Thank Louis DISCLAIMER This message is intended solely for the individual(s) and entity(s) to which it is addressed. It is confidential and may contain legally privileged information. Any unauthorized review, use, copying, storage, disclosure or distribution of this e-mail and any attachments is strictly prohibited. If you are not the named recipient or have otherwise received this communication in error, please destroy this message from your system and kindly notify the sender by e-mail.