Re: javascript dns look up

On Sun, 29 Apr 2007 00:54:14 +0800, shimmyshack wrote
(in article <1177779254.565348.30640@xxxxxxxxxxxxxxxxxxxxxxxxxxx>):

On Apr 28, 5:22 pm, shimmyshack <matt.fa...@xxxxxxxxx> wrote:
On Apr 28, 9:45 am, steve <s...@xxxxxxx> wrote:

hi,
Has anyone come across a "hack" to do a dns look up via JS

I want to evaluate an email address against a server to see if it is
valid ,
I'm 50 % of the way there but i need a way to look up the email servers
MX
record.

I just wondered if there was a way to trigger a dns spew on port 53

Steve

imagine the best case scenario where you have a javascript which can
talk the right protocols and send and receive data from a DNS server,
will port 53 be open on the client.
i shoudl have said "can the client get to port 53 on an external
server" they might be forced to use a proxy on a LAN, or a socks
etc...

The best way is therefore to have
your webserver perform the check based on the value of somepost, and
send back the result via XHR or an iframe, however, I'm not sure that
MX records actually /have/ to exist (I read it along time ago)
although the A record does, and so provided there is at least an A
record you are ok. cacert.org uses pretty good email testing suite you
could purloin, by downloading their source code, which is open
(despite some copyright notices still hanging around) their script
tests the server with a connection attempt without actually sending
them mail. (dont forget to ban all those temporary domains - btw if
you have or find a maintained list of temporary email domians, could
you post a link here) :)


Hi Shimmy,

sorry I do not have any pointers to temp email domain list, I imagine it
changes every day

steve
..

.

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