Exchange Server version details needed for Office 365

The moderators on the Microsoft Office 365 forum have asked me to repost the following question to this site instead:

I am setting up a cloud-based Customer Relationship Management (CRM) solution for my users who do not have a client version of Outlook i.e. we all use OWA for emails and calendar etc. The CRM provider needs to know the version of Exchange Server being used in Office 365 so that they can set up integration but I can’t find this information anywhere. The instructions for ‘Connecting Office 365 to your Outlook desktop application’ aren’t any help in this instance as Outlook won’t be calling for the data.

Can anyone advise please – I don’t want to take a guess!

Many thanks
Peter