Hi,
I would like to know one thing. I am using two ADSL Lines, each from different ISP. And both have a different SMTP Server. Is there any way that Mikrotik can automatically forward traffic to the specified SMTP Server of the current ADSL Connection that is being used, and if the working connection dies, and it shifts to the Backup ADSL Line, it should forward to the specific SMTP server of Backup Line.
I hope i am clear in my question.
Looking forward for a Positive reply.
You can script this… make a script that pings the gw of the main line and if it timesout 4times or so the script just runs some code making the backup line the main line…
Found on the Wiki or forum:
If main GW is up:
/ip firewall nat add action=dst-nat chain=dstnat comment=“SMTP redirect” disabled=no dst-port=25 protocol=tcp to-addresses= to-ports=25
If main GW is down:
/ip firewall nat add action=dst-nat chain=dstnat comment=“SMTP redirect” disabled=no dst-port=25 protocol=tcp to-addresses= to-ports=25
Hi,
Dear QpoX,
I really appreciate your reply, however i dont know anything about scripting in Mikrotik 
That makes us two 
Dont worry…i think someone will help us out.
Mudasir, take a look at the last part of this wiki article. I think it has what you’re after.