To prevent email from being marked as spam in Office 365, you may have 3 options.
- Create a rule bypass spam filter. After login Office 365, go to Exchange admin center>mail flow>rule. Create a rule and add the allowed domain.
2. Add senders to whitelist. In Exchange admin center, go to protection>Spam filter, click edit icon. Under allow list, add the senders’ emails you want to allow.
3. Add allowed domain in whitelist. Same procedure as 2 and add allowed domains.
