Mail: deleting mails older than "x" days

Hi,

in Mail's preferences (Mac OS High Sierra) I can choose to delete mails from the server olther than:

- 1 day

- a week

- 1 month

Unfortunately I need to delete only mails older than 2 months (also 3 is OK) but there is no option to choose a value different from the ones I wrote above.

Is there anything I can do to solve my problem rather than going direcctly to the provider's mail service and doing it manually?

Thanks for any help.

Simon

PS: I apologize if the question is already in the forum but I can't find it.