Re: Office 365 Problem - Outlook: Sending Emails

Hi Sean,

I understand the inconvenience caused by this issue.

I'd like to collect some information to narrow down this issue:
1. Can other users in your organization send emails?
2. Do you get Non-Delivery Reports (NDR) when you failed to send emails? If yes, please post the NDR here for further troubleshooting.

I suggest you try the following steps to troubleshoot this issue:
1. Please check to see if there is an incident in Office 365 Service Health.
2. Try sending an email from Office 365 OWA. If you can send an email from Office 365 OWA, this issue is not related to Office 365 account. It should be related to the settings of the client.

Thanks,
Edward Qu