Hi,
I’m new to MikroTik and having a issue getting my exchange to relay mail.
First I did not make any rule to send SMTP traffik from inside out to external.
telnet SMTP.server.com 25 did not connect.
Then I made a src-nat rule that I thought worked, but it loops on my routerboard to internal SMTP server.
And I’m a bit stuck on how to get this to work. Initial I did not think it was needed setting up a rule for SMTP traffic to work out.
Rules:
[admin@PrimaryInc MikroTik] > ip firewall filter print
Flags: X - disabled, I - invalid, D - dynamic
0 ;;; default configuration
chain=input action=accept protocol=icmp
1 ;;; default configuration
chain=input action=accept connection-state=established
2 X ;;; default configuration
chain=input action=accept connection-state=related
3 X ;;; default configuration
chain=input action=drop in-interface=ether1-gateway
4 chain=forward action=accept protocol=tcp dst-address=10.0.0.2 dst-port=25
5 chain=forward action=accept protocol=tcp dst-address=10.0.0.2 dst-port=3392
6 chain=forward action=accept protocol=tcp dst-address=10.0.0.19 dst-port=3393
7 chain=forward action=accept protocol=tcp dst-address=10.0.0.19 dst-port=54930
8 chain=forward action=accept protocol=udp dst-address=10.0.0.19 dst-port=54930
9 chain=forward action=accept protocol=tcp dst-address=10.0.0.12 dst-port=80
10 chain=forward action=accept protocol=tcp dst-address=10.0.0.2 dst-port=443
11 chain=forward action=accept protocol=tcp dst-address=10.0.0.21 dst-port=3397
12 chain=forward action=accept protocol=tcp dst-address=10.0.0.44 dst-port=3403
13 chain=forward action=accept protocol=tcp dst-address=10.0.0.35 dst-port=3401
14 chain=forward action=accept protocol=tcp dst-address=10.0.0.50 dst-port=5005
15 chain=forward action=accept protocol=tcp dst-address=10.0.0.19 dst-port=45633
16 chain=forward action=accept protocol=tcp dst-address=10.0.0.20 dst-port=3404
17 X chain=output action=passthrough protocol=tcp src-address=10.0.0.2 src-port=25
NAT:
[admin@PrimaryInc MikroTik] > /ip firewall nat print
Flags: X - disabled, I - invalid, D - dynamic
0 chain=srcnat action=accept src-address=10.0.0.0/24 dst-address=10.1.1.0/24
1 chain=srcnat action=masquerade out-interface=pppoe-out1
2 chain=dstnat action=dst-nat to-addresses=10.0.0.2 to-ports=25 protocol=tcp dst-port=25
3 chain=dstnat action=dst-nat to-addresses=10.0.0.2 to-ports=3389 protocol=tcp dst-port=3392
4 chain=dstnat action=dst-nat to-addresses=10.0.0.19 to-ports=3389 protocol=tcp dst-port=3393
5 chain=dstnat action=dst-nat to-addresses=10.0.0.19 to-ports=54930 protocol=tcp dst-port=54930
6 chain=dstnat action=dst-nat to-addresses=10.0.0.19 to-ports=54930 protocol=udp dst-port=54930
7 chain=dstnat action=dst-nat to-addresses=10.0.0.12 to-ports=80 protocol=tcp dst-address=EXT IP dst-port=80
8 chain=dstnat action=dst-nat to-addresses=10.0.0.2 to-ports=443 protocol=tcp dst-address=EXT IP dst-port=443
9 chain=dstnat action=dst-nat to-addresses=10.0.0.44 to-ports=3389 protocol=tcp dst-port=3403
10 chain=srcnat action=src-nat to-addresses=84.49.246.65 protocol=tcp out-interface=all-ppp
11 chain=dstnat action=dst-nat to-addresses=10.0.0.35 to-ports=3389 protocol=tcp dst-port=3401
12 chain=dstnat action=dst-nat to-addresses=10.0.0.50 to-ports=5005 protocol=tcp dst-port=5005
13 chain=dstnat action=dst-nat to-addresses=10.0.0.19 to-ports=45633 protocol=tcp dst-port=45633
14 chain=dstnat action=dst-nat to-addresses=10.0.0.21 to-ports=3389 protocol=tcp dst-port=3397
15 chain=dstnat action=dst-nat to-addresses=10.0.0.20 to-ports=3389 protocol=tcp dst-port=3404
PS!! Nat rule 10 I’ve played around with. And current rule is wrong.
Thanks for any help provided 
/Kenneth