Thanks, Karthik. I received your reply via support, as well, and can confirm (for future reference on this post) that the workaround above works to set the SMTP Server Name to the longer text required for Office 365.
Three years later, and I just encountered this same issue. I haven't yet been able to source a resolution from Ruckus support nor find info online regarding it, although I'm certain others must make use of Office 365 and Ruckus.
