Show pagesourceOld revisionsBacklinksExport to PDFBack to top Share on ... Twitter LinkedIn Facebook Table of Contents Microsoft 365 First Time Login Important General Troubleshooting invalid sender Enable-OrganizationCustomization Microsoft 365 First Time Login First Time Login Important Enable two factor authentication General Check installed Product Key Setup Office 365 Email in Outlook Add new mailbox Using Office 365 DNS Setup a Catch All email http://o365info.com/configuring-catch-all-mailbox-in-office-365-part-1-of-2-2/ https://o365info.com/configuring-catch-all-mailbox-in-office-365-part-2-of-2-2/ https://social.technet.microsoft.com/wiki/contents/articles/30462.catch-all-mailbox-office365.aspx Disable Password Expiry Allow user send as alias Troubleshooting invalid sender Your message couldn't be delivered because you weren't recognized as a valid sender. The most common reason for this is that your email address is suspected of sending spam and it's no longer allowed to send email. Contact your email admin for assistance. Reference: https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/removing-user-from-restricted-users-portal-after-spam?view=o365-worldwide login office 365 admin portal go to Microsoft 365 security at https://security.microsoft.com/restrictedusers if there is any user blocked, select it and click [Unblock] it may take an hour to be effective Enable-OrganizationCustomization The command you tried to run isn't currently allowed in your organization. To run this command, you first need to run the command: Enable-OrganizationCustomization. Need to connect to M365 via PowerShell to enable it. It will take some times (1 hour) to be ready. Then you could go back to the GUI to setup. https://docs.microsoft.com/en-us/powershell/exchange/connect-to-exchange-online-powershell?view=exchange-ps Connect M365 via PowerShell Run Windows PowerShell as Administrator connect to your M365 with this command, replace navin@contoso.com with your username PS C:\Windows\system32> Import-Module ExchangeOnlineManagement PS C:\Windows\system32> Connect-ExchangeOnline -UserPrincipalName navin@contoso.com Run Enable-OrganizationCustomization PS C:\Windows\system32> Enable-OrganizationCustomization The output may display “This operation is not required. Organization is already enabled for customization.”. It is okay and just wait an hour for it to be completed. course/office_365/start.txt Last modified: 2022/05/10 12:51by don.lee