I installed several email servers but the SMTP cannot receive messages.
Let me explain how the DSL network is working here (i don't know the name of the protocol):
Login on a "LAN" which we get the NIC's IP address is something like 10.140.x.x
then login to the ISP's network to get internet access which we get our public IP address.
I pointed the dns to forward all MXE (Mail Easy) to the public IP address.
PROBLEM: the problem is that SMTP is not receiving msgs from outside the "LAN". For instance, if I send an email from my ISP I receive the msg OK. If I sent a msg from hotmail/yahoo the msg never arrives. Note that POP3 is working fine.
I tried about 10-15 mailservers but the problem is still the same. Note also that web/FTP (port:80/21) is OK with dns.