Exchange Online Support

With every Microsoft Office 365 Enterprise, Midsize Business, Small Business, Academic, and Government subscription, Microsoft Support provides global technical, pre-sales, billing and, subscription support. Support is available both online through the Office 365 portal, and by telephone for both paid and trial subscriptions. For more information, see Office 365 Support Options.

Authorized administrators can use the Office 365 portal to submit service requests online, access support telephone numbers, and view all open and closed service requests. For instructions, see Contact support for technical, pre-sales, billing, and subscription issues.

Please Use the following Articles for reference,

Microsoft Support Components: https://technet.microsoft.com/en-us/library/jj945184.aspx

Office 365 for business—support options: https://office.microsoft.com/en-us/business/office-365-for-businesssupport-options-FX103843554.aspx

Support: https://technet.microsoft.com/en-us/library/jj819269.aspx