Home |
Search |
Today's Posts |
#1
Posted to microsoft.public.excel.programming
|
|||
|
|||
Validate an Email Address
Hi Guys,
I wondered if it was possible to design a simple form with one textbox and a submit button that would validate an email address put in the textbox to see if it was a correct email address. (i dont mean the syntax/format, but actually a real email address) I have seen an article on how to do it in PHP (http://www.sitepoint.com/article/use...il-address-php) but I would prefer to do it through a userform Does anyone know if this is possible? Duncan |
#2
Posted to microsoft.public.excel.programming
|
|||
|
|||
Validate an Email Address
take a look at dnsstuff.org. You could possible simulate a form post and
read the response via xmlHttp. Otherwise, you could simulate the handshake with a given SMTP server and perform the whois. have a look at http://www.vbip.com/winsock-api/ to get you started on implementing winsock. sample flow 1. validate smtp address format 2. perform DNS Lookup of the domain to see if it exists 3. perform MX Lookup of the domain to see if it has a mailexchanger exposed (get the one with the lowest meteric) 4. ( connect to the MX server issue a Helo [<"Domain you are talking to"] read response if 250 then issue a MAIL FROM: <"someemailaddress" read response if 250 then issue a RCPT TO: <"email_address_you_are_testing" read response if 250 then email address exists, or the server is not telling us else email address doesn't exist issue Quit close connection ) Using an api winsock will make deployment easier then requiring the winsock control to be install on target machines. Using API have risks that you should be aware of. First, improper calls can crash you application and cause data loss or they can provide you with a nice BSOD with a unitelligable GPF. Error handling is your friend, comment your code (because if you do, it forces you to rationalize what you are doing to maintain focus.) Remeber, with API's, if you issue an open of some sort, you should call the appropriate close routine when you are done. API's do not have "auto cleanup". Sockets are asynchronous by design, once you issue a command, you will not have immediate feedback and will therefore be blocking until a response is returned. Not all bad SMTP response codes are bad, and perhaps you should issue the command again to try for a positive response. HTH "Duncan" wrote in message oups.com... Hi Guys, I wondered if it was possible to design a simple form with one textbox and a submit button that would validate an email address put in the textbox to see if it was a correct email address. (i dont mean the syntax/format, but actually a real email address) I have seen an article on how to do it in PHP (http://www.sitepoint.com/article/use...il-address-php) but I would prefer to do it through a userform Does anyone know if this is possible? Duncan |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
How to validate email address during data entry in Excel | Excel Discussion (Misc queries) | |||
Validate Email address entry | Excel Discussion (Misc queries) | |||
Validate email address | Excel Programming | |||
Validate an email address | Excel Programming | |||
relative address in validate | Excel Programming |