I have an issue configuring policy NAT. my design is attached
I've One SMTP Server with two IP adresses. the new is 10.3.25.2/24 and the old one 192.168.56.2/24. the first IP should replace the second after a period of time.
I would like to translate the old 192.xxx IP to the fisrt one for my customers who still use this old wheras customers who started using the new IP should not be translated.
My SMTP Is in my DMZ and my customer are at the outside (Internet)
Could some one help me configure this policy NAT.
I have one SMTP server with