In 2013, over 100 billion business e-mails were sent every day. According to the Radicati Group, that number is expected to exceed 132 billion e-mails per day by 2017.

That means approximately 100 e-mails hit your in-box per day. No wonder it’s so hard to keep your in-box relatively clean.  Here are some tools that can help:

Mailbox - Mailbox makes it easy to organize your in-box from your smartphone. You can quickly archive, delete or save messages for later. You can even add e-mails to your to-do list so you never forget about a message you don’t have time to address when it first arrives.

The Email Game - The Email Game turns responding to and archiving e-mails into – you guessed it – a game. Skip an e-mail and you lose 25 points; respond to one and you gain 175 points. You can also challenge yourself to sort through your e-mail in a set time period.

Unroll.me - Sorting through all the e-mail you’ve subscribed to (or been subscribed to) can be tough. This service takes all your subscription-based e-mails and transforms them into a daily digest.

SaneBox - SaneBox moves unimportant e-mails out of sight so you can focus on your most important tasks. SaneBox uses an algorithm to filter through your e-mails and put nonessentials into a folder for you to look at later; that way you can focus on the important stuff.

ActiveInbox - If you use Gmail, ActiveInbox turns e-mail into a task management system. You can categorize tasks as “action,” “waiting on” or “overdue.” If you need something done on a certain day, you can schedule it on your calendar and receive a reminder.