Attachments.me is a simple extension, available for Google Chrome and Firefox that connects cloud storage services with your Gmail account, allowing sharing of any item stored online as if it were an email attachment. Up until recently, it worked only with Dropbox, Google Drive and Box but now SkyDrive has been added to the list.
The extension integrates beautifully in Gmail and it also lets you send an incoming attachment straight to a cloud folder based on user-defined rules. Support for SkyDrive can help you send Word documents to Microsoft's cloud.
Furthermore, the service automatically crawls your email account and indexes all attachments. As far as security is concerned, the service uses bank-level encryption.
Attachments.me