We have often encountered that our emails have not been delivered to hotmail.com, outlook.com, msn.com, or live.com account. Please set the following settings before sending an email. This setting is unable to do with the Outlook Mobile App. Yow will need to login to outlook.com web mail.
① Log in to your account and click on the Settings (gear) icon at the top right.
② Click View all Outlook settings
③ Scroll down and select the Safe mailing lists tab. Click + Add and enter the email address as below.
④ Click Save at the top right.The configuration is complete.