> On 12 Jan 2015, at 08:29, David Hofstee <da...@mailplus.nl> wrote: > > Hi Mike, > > About trying to hit the mail ports... It is very easy for a domain to set its > MX to a random host name. So before you block you might want to check the > To-domain in the header of the mail. Otherwise it is too easy to DoS yourself > (by planting email addresses in systems, such as mine, and then changing the > MX of that domain to your hosts). >
Should be overcome by good dont block range checker and header checks as above Colin
