We require that email eater ignore mail when the subjet of mail is equal to summary of ticket created in service desk.
Is this possible??
I don't think so.
The Filter rules that apply to inbound email get applied, and then if the mail passes that test it gets processed.
For example, you could check for text "Out of Office" in the email, but you could not check the ticket Description for "Widgets International" and then allow the email to update the ticket if a match was found.
See here for the standard functionality:
Define a Mailbox - CA Service Management - 17.2 - CA Technologies Documentation
It's a bit of an unusual requirement . . . often outbound email notifications WILL contain the Subject in them, which means that most people replying to those tickets will also contain the Subject. Maybe you could explain the bigger picture and we see if there is another way to achieve the underlying goal?