Microsoft CRM supports tracking of e-mail messages and e-mail messages often come with attachments. If you want to prevent Microsoft CRM from storing an e-mails attachments you can set the file size within Configuration to 0.
What if you don't want to block all attachments or what if you inherited a system that has a ton of attachments stored in the database?
You can purge e-mail attachments from the CRM Database.
Take a look at the EMEA Support Teams Blog Post on the subject for more.