Here is another strange bug

[Rick2025]

I got this from another group

If you take a student account and put the word green in the subject line and add no message body, then email it to a staff member, the message bounces. Staff does not behave the same and the message goes through. 

Go figure

[Kim_Nilsson]

Check your Content Compliance rules.

Could be a word list block, set on the student OU.

[Bill_Gibson]

I can not reproduce this.