Hi!
today we found out that e-mail which is sent by one of our partners is not imported to our JSD.
So after troubleshooting I found that their mail is being rejected by bulk filter. What I'm not able to find out is why they are considered bulk email or how could I whitelist them or turn off this filter.
I would be happy if someone could point me in the right direction 
edit: As additional information I have found out that they started using Jira SD, so those rejected emails are being sent from their Jira SD instance.