I'm trying to match a numeric header value to between 300 and 999.
The condition is "when the message header matches text patterns"
I'm using ^(3|4|5|6|7|8|9)\d\d$ based on https://technet.microsoft.com/en-us/library/aa997187%28v=exchg.141%29.aspx
It's working for 300-999, but it's also matching values like 85 and 215. It seems to match any value with at least 2 digits.
Is my regex correct? Does regex work correctly for header values?