Auto Reply or Autoresponder

Hi

I am looking for tool or script that can auto reply based on keyword in the subject line with different reply.

for example

subject : Part No 1234

I want to auto reply this email with message which only relates to Part 1234

Then someone else sends email with Part No 4567

I then want to send different reply which only relates to Part No 4567


I looked into Gmail but Gmail doesn't have auto reply, only vacation setting and it send the same message.


Is there anything that can do this?

Thanks