Re: What this means "(\w|-)+@\w"? [message #175017 is a reply to message #175012] |
Wed, 03 August 2011 13:46 |
Peter H. Coffin
Messages: 245 Registered: September 2010
Karma:
|
Senior Member |
|
|
On Wed, 03 Aug 2011 10:55:32 +0200, ?lvaro G. Vicario wrote:
> El 02/08/2011 14:56, Peter H. Coffin escribi?/wrote:
>
>> Several years ago, I wrote an email validator that worked fairly
>> will, and handled address cases that hadn't even been thought of yet.
>> It used telnet to fake being a MTA to the MX of record for the domain
>> through enough steps to ask if the receiving MTA would actually
>> accept mail for the address, but stopping short of actually sending
>> anything.
>>
>> It was, however, really slow, to start up. Once it had everything
>> cached up, it could average a couple of email addresses being
>> validated per second, but the first few hundred took a half hour or
>> so.
>>
>> I wonder what happened to that code....
>
> I've never understood the obsession for writing e-mail validation
> routines that not only check for syntax errors but try to find out
> whether the mailbox actually exists. Nobody would install a modem on
> the server so it can be used to validate phone numbers...
Heh. In North America, there's a comparable data file to this kind of
thing available from nanpa.org that (while not getting down to the
actual phone number level) will tell you whether a given combination
of area code and exchange (the M and N parts of +1 MMM-NNN-XXXX) are
valid, in service, on hold, pending allocation, and who runs them so
you can get a good idea of whether they're a land line, a mobile, a
specialty service, and sometimes even a stab at whether it's a business
or residence. EG: An owning organization of "AT&T BUSINESS SVCS" is
probably not someone's residence, and "ACS WIRELESS DBA ALL-TEL" is
probably a mobile. So, yeah, you CAN do it with phone numbers and it
doesn't even require a modem.
> Whatever, considering it as proof of concept, your code was a nice
> exercise. Too bad it could not detect typos when the mistyped address
> exists as well.
Not if the typo led to another valid address, no. If the typo led to the
mail failing, it would be caught. The "fix commonly mistyped domains"
part never got written, either. The idea behind that is to process only
the failures and remap to big services (yaho.com to yahoo.com, etc.),
then re-test.
--
"Only Irish coffee provides in a single glass all four essential food
groups: alcohol, caffeine, sugar, and fat."
-Alex Levine
|
|
|