Office 365 Key Benefits

Access to e-mail, documents, contacts and calendars on nearly any device
Simple and highly secure collaboration with colleagues and business partners
Business-class features, such as IT-level phone support, financially backed 99.9 percent uptime, geo-redundancy, disaster recovery, and robust security and privacy controls and standards
Comprehensive solutions, such as desktop productivity applications, portals, extranets, external websites, instant messaging (IM), voiceconferencing, videoconferencing, webconferencing, e-mail and voicemail.
Pay-as-you-go pricing options, which provide predictability and flexibility for all or part of an organization

What’s Included

Microsoft Office
Exchange Online
SharePoint Online
Lync Online

Office 365 Plans

Office 365 for Small Businesses

This is an easy-to-use set of Web-enabled tools for small businesses, independent consultants and professionals looking for business-class productivity services. It works with the tools people know and use today. Benefits include the following:

Office Web Apps for viewing, editing and sharing documents
Large 25GB mailboxes for each user and the ability to send attachments up to 25 MB
Easy-to-use design tools to build a professional-looking website quickly
Password-protected team sites for collaborating on documents and information
Industry-leading, always-up-to-date antivirus and anti-spam solutions
Integrated IM, presence and online meetings with audio and videoconferencing and multiparty data sharing
Financially backed, guaranteed 99.9 percent service uptime
24×7 moderated community-based support
Your DNS services for your vanity domain. (Delegation of your DNS is required for this plan)

Example:
Organizations with one to 25 users (maximum 50) that have minimal IT resources. Organizations that require Active Directory Federation Services, archiving for legal compliance, BlackBerry Enterprise Server or phone support should consider Office 365 for enterprises.
Price: $6 per user, per month

It includes the following:

Office Web Apps Web productivity applications
Exchange Online for e-mail, mobile access, calendar, contacts, discovery, antivirus and anti-spam
SharePoint Online for Microsoft Office Access services, team sites and an easy-to-build public website
Lync Online for instant messaging and virtual meetings
Community support
Simplified setup and management

Office 365 for Enterprises

Large 25GB mailboxes and the ability to send attachments up to 25 MB
Financially backed, guaranteed 99.9 percent uptime service level agreement
24×7, IT-level support over the phone, the Web or e-mail
Single sign-on capabilities with local Active Directory
Latest version of Office Professional Plus, connecting users to communication and collaboration services
Office Web Apps for viewing, sharing and minor editing of documents directly from a browser
Industry-leading, up-to-date antivirus and anti-spam solutions
Integrated IM and presence, online meetings with audio and videoconferencing, and multiparty data sharing
Team sites to share, manage and search for information and resources
You maintain control of DNS services for your vanity domain.
Enhanced Administrative Control of Exchange via Power Shell 2.0

Example for Existing BPOS Customers

Existing customers of Microsoft’s Business Productivity Online Suite receive the same services with new enhancements.

List price: $10 per user, per month

Exchange Online, including e-mail, mobile access, calendar, contacts, archiving, discovery, antivirus and anti-spam
SharePoint Online, including advanced sites for collaboration, social computing and My Sites, content management and people search.
Lync Online, including IM and virtual meetings
24×7 IT-level phone support
On-premises licenses
Control and management features

Example with Office Desktop Software and Enterprise Features

For organizations that want Office Professional Plus desktop software along with the full functionality of Exchange, SharePoint and Lync Online.List price: $24 per user, per month

Office Professional Plus desktop software
Office Web Apps web productivity application
Exchange Online, including e-mail, mobile access, calendar, contacts, advanced archiving, discovery, anti-virus, anti-spam and voicemail in the inbox, SharePoint Online, including advanced sites for collaboration, InfoPath Forms, Access, Visio, and Excel services
Lync Online, including IM, virtual meetings and on-premises voice
24×7 IT-level phone support
On-premises licenses
Control and management feature

Caveats I have Discovered

These will be updated as I discover anything that isn’t covered in the text above.

Office 365 for Small Businesses (P1)

When you delegate your domain name to the O365 servers, you can only add new A and CNAME records. If you need some more advance DNS services, this is not currently available.
SharePoint (and Office Web Apps) are not protected by SSL.
If you have software monitoring systems that send status emails to a special mailbox, you will have to implement a work around.
You can only select from a standard set of retention policies for the mailbox folders.

Office 365 for Enterprises (E1, E2, E3, E4)

The SharePoint Online server is not ready for you to create new document in anything but Word without some extra setup. In the P1 plan this feature is ready to go.
If you have software monitoring systems that send status emails to a special mailbox, you will have to implement a work around. This is the same for the P1 plan, but the work around options are more readily available.
Custom retention policies can be created and added to mailbox folders.