Fix error message "Email address user@domain is not valid" when try to send an email via Outlook 365

Job ID: 37273803

Budget: $8 – $15 USD

I am seeking a freelancer who can help me fix an error message that occurs when I try to send an email via Outlook 365. The error message states "Email address user@domain is not valid."

Requirements:
- Experience with Outlook 365 and email troubleshooting
- Ability to identify and resolve issues related to email addresses
- Familiarity with email protocols and standards

Skills:
- Strong knowledge of Outlook 365
- Proficiency in email troubleshooting and error resolution
- Understanding of email protocols and standards

Please note that the error occurs with any email address and is consistent across all platforms. I have not been able to send emails via another device or platform.

Enclosed the error message and how it looks the same user but registered in 365 with another mail.