UPDATED June 2016.
Yes. You can use any account type you currently have to sign up for a free trial of attachedapps. Please note the difference in account types below.
Email account types vary. The most common types are POP3, IMAP and Microsoft Exchange Server accounts. POP3 stands for Post Office Protocol.
Most home users usually have POP3 email accounts with an Internet Service Provider (ISP) or they use a Web-based email service like Windows Live Mail. Internet Message Access Protocol (IMAP) is similar to a POP3 but has some additional features and benefits you don’t get with POP3. For example, Gmail is IMAP type.
Microsoft Exchange is an e-mail-based collaborative communications server for businesses. Most home and personal accounts do not use Exchange. People without Exchange accounts cannot use the features in Outlook that require Exchange. In order to deliver the full functionality of attachedapps, we require a connection to an Exchange server. This connection enables the integrated features we offer such as the ability to import your contacts and sync information from the apps back to Outlook. If you are unsure whether or not your email account runs over a Microsoft Exchange Server, please contact your service provider to confirm.
You can use any Email account to sign up for attachedapps and will still have the ability to enable an Exchange integration if you wish to pair your attachedapps account with one. Here's more information on the Exchange integration.