If you have any problems on Office 365, here you have the Tools to Troubleshooting your problem

This set’s of tools is to identify the root cause of your problem.

Checks

Check your Office 365 configuration with Office 365 health, readiness, and connectivity checks ;
Run checks to help determine the status of your on-premises or cloud configuration.
Details | Prerequisites

Check your on-premises Exchange Server with the Office 365 Best Practices Analyzer (beta)
Requires Exchange Server 2013.
Details | Prerequisites

Check your Office or Office 365 connectivity with the Microsoft Connectivity Analyzer
Requires Windows Vista or higher, with Microsoft .NET Framework 4.5.
Details | Prerequisites

Check your network connectivity with Exchange Client Performance Analyzer (ECPA)
Run checks to help determine the health of your network.
Details | Prerequisites

 

Deployment wizards
Choose an Office 365 service for self-guided deployment support