I have facing very much problem of SMTP traffic , lots of unknown outside the network used my mail server SMTP port,
heavy much mail send through my mail server ( used SMTP port) from outside network.
I need it to block smtp port from outside network , only allowed from my network.
i am using Cisco 3845 router.
my Mail server IP 184.108.40.206
If I put in access lists for each range and nothing else associated with SMTP would that accomplish the task?
Allowing SMTP traffic from on a few IP ranges ( my network only BLOCK outside network need to configure my Cisco 3845 to only allow SMTP traffic from certain IP ranges to my mail server
so what i can do to solve this issue.
my network 220.127.116.11/22
So plese give me the soluction regarding the same.