Firewall rule for my zimbra

[mvalenzuela.cl]

I have a doubt with a firewall rule for my zimbra. Now I have next rules in my Firewall :
This Firewall is shorewall

Part of my files /etc/shorewall/rules

#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL RATE

DNAT net dmz:10.8.1.10 tcp http - IP_public
DNAT net dmz:10.8.1.10 tcp 25 - IP_public
DNAT net dmz:10.8.1.10 tcp 110 - IP_public
DNAT net dmz:10.8.1.10 tcp 143 - IP_public

I really think the port 25 must be closed to net interface, but if I apply that rule not receive emails from other email servers, I only receive mail from the same mail server.

As I set a rule for my server to receive email from other servers have port 25 closed?.

I do not understand how it affects the port 25 to receiving mail from other servers in zimbra, in sendmail did not have this problem, it sure is a mistake of mine, but I do not understand.

Saludos

[ArcaneMagus]

Port 25 is the SMTP port... which virtually ALL mail is communicated by, so obviously blocking it will block all incoming mail. I am not sure how sendmail did not use that...

[mvalenzuela.cl]

Ok, I can Understand

Thaks you!