O365 users message from the same organisation going straight to spam

[ChrisH]

We increasingly have a few users, sometimes random emails going straight to spam. This is just simple messages from one user to the other on the same tenant. What is the best way to to try and stop this, some sort of mail flow rule or another setting?

[Steve21]

We have a default mail rule of internal mail goes to -1/Bypass on the SCL

 

No doubt you could do some fancy work with why it's getting hit, but as a quick catch-all

 

Steve

[chaplic]

I would be very, very surprised to see an email from one user on a tenant straight to another going into spam. Are you sure some odd connector isnt sending it out of tenant and back in? Whats does message tracking say? is your SPF record current and including office?

[ChrisH]

Thank you everyone, I have stuck that rule in for now and I will have a look at the things you have highlighted chaplic.