Support intro
Sorry to hear you’re facing problems 
help.nextcloud.com is for home/non-enterprise users. If you’re running a business, paid support can be accessed via portal.nextcloud.com where we can ensure your business keeps running smoothly.
In order to help you as quickly as possible, before clicking Create Topic please provide as much of the below as you can. Feel free to use a pastebin service for logs, otherwise either indent short log examples with four spaces:
example
Or for longer, use three backticks above and below the code snippet:
longer
example
here
Some or all of the below information will be requested if it isn’t supplied; for fastest response please provide as much as you can 
Nextcloud version (eg, 20.0.5): 23.0.2
Operating system and version (eg, Ubuntu 20.04): Docker
Apache or nginx version (eg, Apache 2.4.25): Docker
PHP version (eg, 7.4): 7.4
The issue you are facing: mail
Is this the first time you’ve seen this error? (Y/N): N
Steps to replicate it:
- Sent mail to office365 address, using office365 smtp server
- Check the mail
- It is classified as junk. gmail or other mail service is not.