Email template

Email template

Hello,
Our helpdesk is working with internal and external employees. For this purpose we use 2 different emails.
I want to set the automatic response "Acknowledge contact on receiving a new ticket" for these two emails: from Support email to be sent to the customers, from Employee email - to internal users.
How can I separate this? By separate template? Then, how to set the condition. There is a "Reply to" field, but I did not find, how to apply it.
Thank you in advance.
Best regards,
Marta Melnyk