My calendar invitations and emails are marked as spam and are bouncing back

Welcome Peter Nkansah,

Thank you for reaching out to Microsoft Q&A forum.

Before proceeding, could you confirm whether you are sending from a personal Outlook.com/Hotmail/Live account or a work/school Microsoft 365 account?

If it is a personal Outlook.com account, please try these steps:

1, Send a test email to yourself

• Open Outlook.com
• Create a simple message without attachments or links
• Send it to your own email address
• Open the received message and reply to it.

2, Test another recipient

• Send the same simple message to a different recipient
• This will help determine whether the rejection occurs with every recipient or only particular addresses/domains

3, Check the complete bounce-back message

• Open one of the failed-delivery messages
• Scroll down to“Diagnostic information for administrators”
• Please share the error description shown there, but remove any email addresses or other personal information first.

4, Ask one affected recipient to add your address to their Safe Senders list

• Then send them another simple test message

Looking forward to your update.