Microsoft email service provides the ability to create addresses on different domains, including corporate ones.
Since this is a major foreign service, its attitude to spam is very serious.
We strongly recommend not sending letters to corporate addresses — usually no real subscribers use them to receive mailings.
If emails are tagged as spam by Microsoft, you will see information about this in the details of the error.
In this case, you need to go to the link https://sender.office.com/ and fill out the form.
In the «Email» field, specify any email address available to you — for example, your personal mailbox.
After that, you will receive a letter to the specified email, it will contain a link that you need to click on. This will exclude the IP address from the blacklist.
Another situation is with @outlook.com addresses, where all decisions on the blacklist are made completely automatically.
If you find yourself in spam on Outlook, the only way out is to not send any emails and notifications to @outlook.com for 4 days. After that, the blacklist will be reset and you will get out of spam.
We also recommend a detailed article on what factors affect email deliverability.
Choose a country