One of the best apps for Windows Phone 8 is called Mail Plus. At first glance, it might not look like anything much, but it is quite powerful, and it's only $1.99. The app is great for those who want more file management features from their Windows Phone 8 device, and it does not disappoint. 

Mail Plus enables you to attach files from your SkyDrive, images from your phone and files received as attachments from your inbox. It also makes it possible to upload your images from your phone and files received as attachments to your SkyDrive. By connecting your inbox, SkyDrive and your phone, Mail Plus heavily increases your smartphone's file-managing capabilities. 

Features: 

• Send emails with attachments of any file type from SkyDrive, Inbox and Pictures Hub 

• Save attachments from your inbox to your SkyDrive/Smartphone 

• Save your pictures to SkyDrive (in original resolution) 

• Attach multiple pictures and files at the same time 

• Cc and Bcc support 

• Drafts support 

• Cellular data connection warning 

• SMTP for outgoing, POP3 for the incoming emails 

• The app adapts to the background theme of your smartphone

• Trial version doesn't expire 

Limitations: 

• Maximum size of an attached file: 10 Mb 

• Maximum size of total attachments: 25 Mb 

• Maximum Number of attached files: 125 

• Maximum number of recipients: 125 

• Maximum length for subject: 255 

Limitations of the Trial version: 

• Allowed file extensions: "jpg", "png", "xlsx", "pptx", "docx", "xls", "ppt", "doc", "pdf", "csv", "txt" 

• Maximum Number of attached files: 5 

• You can't use the files from Inbox section 

There are a few performance problems here and there, but nothing noteworthy. What matters most is that Mail Plus does what it says it can do, which means you'll be very happy with the outcome. 

If you want to give Mail Plus a spin, jump to the Windows Phone Store here and test it out via the free trial option.