Forwarding rule not working if *.pdf in mail header

[TargetedIT]

I have a rule set up to forward email to our accounts system based on conditions:

If subject or body contains "Invoice" or "invoice" or "Credit Note" or "Statement" or "Remittance"
and which has an attachment
then forward it to (accounts system email address)
except if subject or body contains "Pro Forma Invoice"

The rule works as it should. What I would really like is for only emails that have pdf attachments to be forwarded. At the moment, attachments such as jpg or png are being forwarded, needing to be cleaned up in the accounts system.

I have tried including with "*.pdf" in the message header but, nothing gets forwarded until I remove that condition.

I would also like to remove any jpg or png that are included with emails that should be forwarded.

Is there a way to achieve what I am trying to do?

I look forward to any suggestions.



Graham