Subject: Absent

Description: I will be away from this date to this date.

Usually I add the subject to the spam filter subject field and this stops the loop from being repeated if the user is recontacted while being away but in this case, I can't just add the word "Absent" to the spam filter as this will ignore all e-mails that have Absent in the subject line and since HR is using the service desk they sometimes receive requests that say Absent is missing from system for example. I tried to add the description to the spam filter description, I added the whole sentence "I will be away from this date to this date" but when I tested it, the request still came through the service desk and restarted the loop. I don't know how the description works in the spam filter, does the filter read the whole e-mail before intercepting it?  Since this solution doesn't work, how could I prevent this from happening? I have moved that particular e-mail to another folder in the mailbox so servicedesk doesn't fetch it but if technicians contact that same person, the loop will restart as this is an auto-reply on the end user side.

I am running service desk plus 9.2 build 9234 with an MSSQL database.