Attachment is removed while forwarding an email using pre parser rule.
Steps to replicate:
1. Create a parser rule with any criteria For ex. "Email Queue: Equal: Queue_Name" and forward it to a custom email using Forward To field (pre parser) under Actions tab.
2. Mail an email with attachment to the Email Queue,
3. The mail received on custom email defined in "Forward To" field loses the attachement though the attachement is parsed in the helpdesk.