Unsubscribe link

Your unsubscribes are probably routed through a simple Unsubscribe Form in Marketo. The easiest thing to do would be to craft a simple alert email with the Marketo Alert token {{SP_Send_Alert_Info}}, then setup a Smart Campaign as follows:

Fills out Form (trigger) > Form Name IS > Unsubscribe Form (probably what it's named)
Send Alert > Your Alert Email > Send To NONE > To Other Emails: (your email address)

I did try to create an alert and the way I did it was - having the unsubscribe link at bottom linked to lanidng page (External URL)

And including the munchkin code  on that URL . and then i wanted to setup an alert . with the flow - Clicks link - send alert emaik.

But unfortunately I cant see my URL i click link drop down (despite putting munchkin tracking code)

Yeah, if you have the Munchkin code on an external URL, you won't be able to see your links in the dropdown menu. However, if you just copy + paste the link into your Marketo filter, everything should work fine. Just watch for that red squiggly line underneath the link, which lets you know Marketo can't see that link. You may need to remove the "http://" prefix.