With HelpDesk 3 and Cloud Desk 3 you can use any email account to pull in support requests. The build in php imap feature will pull in the email and create a ticket and also a new user account if you whish so.
Since Version 3.5.9 you can also choose if attachments should be sent to the customer and attachments from the customer are getting pulled into HD3 as well. To activate this feature go to your operator panel - settings - php imap and edit any of your connection.
On the edit view you will have two new options like the one in the screenshot below: