Even with all the improvements Apple has made to the iPhone’s Mail app in iOS 5, there are still some glaring omissions, especially if you’re the kind of person who likes to create folders and have them populated based on a selection of rules.

Smart folders are something that Apple has embraced on the desktop, with Mail on OS X featuring them heavily, which makes it all the more surprising that they haven’t brought them to its mobile platforms.

As always, the jailbreak community has some to the rescue, and SmartFolders is just what the doctor ordered…

What SmartFolders does is actually fairly obvious – the extension creates virtual mailboxes, and allows users to specify what rules are applied to emails. The result of the rules applied decides which virtual mailbox the emails show up in. It’s not rocket science, but it’s useful to the Nth degree, depending on how much time you put into it.

The rules that can be applied are actually quite comprehensive, with the criteria covering all the usual bases, and some.

The criteria include:

  • Account
  • Folder
  • Heading
  • Sender
  • Receiving
  • Object
  • Summary
  • In the inbox
  • It is / is not marked
  • It is / was not read
  • Has / has not been answered
  • Presents attachments
  • It was received before / after this date

SmartFolders can be given custom names, and custom labels too, meaning you can really go to town on your own mailboxes.

This is just another case of the jailbreak community doing what Apple should probably have already done, and it’s something that Android users already experience thanks to the power of Gmail.

SmartFolders is available via the BigBoss repository now, and costs $1.99.

Go jailbreakers!