Re: Email Id Verification
On 2012-05-25, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: On Thu, 24 May 2012 05:32:16 -0700, niks wrote: Hello everyone.. I am new to asp.net... I want to use Regular Expression validator in Email id verification.. Why do you want to write buggy code that makes your users hate your program? Don't do it! Write good code, useful code! Validating email addresses is the wrong thing to do. I have to agree with Steven. Nothing will make your users swear at you as certainly as when you refuse to accept the e-mail address at which the reeive e-mail all day every day. -- Grant Edwards grant.b.edwardsYow! I appoint you at ambassador to Fantasy gmail.comIsland!!! -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Fri, 25 May 2012 13:36:18 + (UTC), Grant Edwards wrote: [snip] . . . Nothing will make your users swear at you as certainly as when you refuse to accept the e-mail address at which the reeive e-mail all day every day. Amusingly, every time I log into Discovercard's web site, I get a red-letter warning that my registered email address is invalid. Inquiring, I was told that the presence of the substring spam anywhere in the address (including @spamcop.net) makes the address invalid in Discovercard's opinion. -- To email me, substitute nowhere-spamcop, invalid-net. -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Sat, May 26, 2012 at 2:25 AM, Peter Pearson ppearson@nowhere.invalid wrote: Amusingly, every time I log into Discovercard's web site, I get a red-letter warning that my registered email address is invalid. Inquiring, I was told that the presence of the substring spam anywhere in the address (including @spamcop.net) makes the address invalid in Discovercard's opinion. I had no idea it was so easy to prevent spam from getting through. I am in awe, Discovercard! Yet, invalid or not, it apparently works for you? ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Fri, May 25, 2012 at 10:33 AM, Chris Angelico ros...@gmail.com wrote: On Sat, May 26, 2012 at 2:25 AM, Peter Pearson ppearson@nowhere.invalid wrote: Amusingly, every time I log into Discovercard's web site, I get a red-letter warning that my registered email address is invalid. Inquiring, I was told that the presence of the substring spam anywhere in the address (including @spamcop.net) makes the address invalid in Discovercard's opinion. I had no idea it was so easy to prevent spam from getting through. I am in awe, Discovercard! I would think that it is not an anti-spam measure, but simply due to the fact that most addresses containing spam tend to be something like nos...@invalid.net, being either a fake address or a junk inbox that is only checked when an important mail is expected. -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Sat, May 26, 2012 at 3:04 AM, Ian Kelly ian.g.ke...@gmail.com wrote: I would think that it is not an anti-spam measure, but simply due to the fact that most addresses containing spam tend to be something like nos...@invalid.net, being either a fake address or a junk inbox that is only checked when an important mail is expected. If it's fake, you'll find out when you send to it. If it's checked only when important mail is expected, you accept it. I'm not seeing a problem here. I have a @yahoo.com.au address that is used solely in the latter form; it's checked maybe once or twice a month (in comparison to my two primary accounts, which both alert me on incoming mail, one of them in direct response to the SMTP server receiving it); and if any form rejects it, that's flat wrong. DNS lookups aren't particularly expensive. A check for whether the domain has an MX record will catch most forms of fakery without needing any extra effort. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On 25May2012 13:36, Grant Edwards invalid@invalid.invalid wrote: | On 2012-05-25, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: | On Thu, 24 May 2012 05:32:16 -0700, niks wrote: | Hello everyone.. | I am new to asp.net... | I want to use Regular Expression validator in Email id verification.. | | Why do you want to write buggy code that makes your users hate your | program? Don't do it! Write good code, useful code! Validating email | addresses is the wrong thing to do. | | I have to agree with Steven. Nothing will make your users swear at | you as certainly as when you refuse to accept the e-mail address at | which the reeive e-mail all day every day. And it will get better. If the validation code is sufficiently widespread, the user may be unable to complain or report the issue. -- Cameron Simpson c...@zip.com.au DoD#743 http://www.cskk.ezoshosting.com/cs/ Don't have awk? Use this simple sh emulation: #!/bin/sh echo 'Awk bailing out!' 2 exit 2 - Tom Horsley tahors...@csd.harris.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Friday, 25 May 2012 14:36:18 UTC+1, Grant Edwards wrote: On 2012-05-25, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: On Thu, 24 May 2012 05:32:16 -0700, niks wrote: Hello everyone.. I am new to asp.net... I want to use Regular Expression validator in Email id verification.. Why do you want to write buggy code that makes your users hate your program? Don't do it! Write good code, useful code! Validating email addresses is the wrong thing to do. I have to agree with Steven. Nothing will make your users swear at you as certainly as when you refuse to accept the e-mail address at which the reeive e-mail all day every day. -- Grant Edwards grant.b.edwardsYow! I appoint you at ambassador to Fantasy gmail.comIsland!!! Ditto. This would be my public email, but (like most I believe) also have 'private' and work email addresses. For the OP, just trying to check an email is syntactically correct is okay-ish if done properly. Normally as mentioned you just send a confirmation email to said address with some id and link that confirms (normally with an expiry period). Some mail servers support the does this mailbox exist? request, but I fear these days due to spam, most will just say no -- so the only option is to send and handle a bounce (and some don't even send back bounces). And a pretty good way for malicious people to make mail servers think you're trying a DoS. Although, what I'm finding useful is an option of auth'ing with twitter, facebook, google etc... Doesn't require a huge amount of work, and adds a bit of validity to the request. Jon (who still didn't get any bloody Olympic tickets). -- http://mail.python.org/mailman/listinfo/python-list
Email Id Verification
Hello everyone.. I am new to asp.net... I want to use Regular Expression validator in Email id verification.. Can anyone tell me how to use this and what is the meaning of this \w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)* -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Thu, May 24, 2012 at 10:32 PM, niks nikunjparmar...@gmail.com wrote: Hello everyone.. I am new to asp.net... I want to use Regular Expression validator in Email id verification.. Can anyone tell me how to use this and what is the meaning of this \w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)* This is a mailing list about Python, not ASP, and not regular expressions. Every regex library is different, some more than others, so your best bet is to find documentation on the actual function/library you'll be using. But I would strongly recommend NOT using a regex to validate an email address. It's prone to false positives and false negatives. There are, unfortunately, many systems around which do not accept legal addresses (for instance, this.is.vali...@rosuav.com is, as the name suggests, quite valid - as is fred_foobar@[203.214.67.43]); part of the blame can be laid on PHP's inbuilt validation functions, but I know that several are implemented using a fairly simple and brutally wrong check. Validate the domain part (the bit after the @) with a DNS lookup, nothing more and nothing less. If you absolutely must do a syntactic/charset check, read the appropriate RFCs and figure out what really is and isn't legal. You will be surprised. (For instance, foo@localhost is a perfectly valid address, because localhost is a top-level domain.) Chris Angelico -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Thu, 24 May 2012 05:32:16 -0700, niks wrote: Hello everyone.. I am new to asp.net... I want to use Regular Expression validator in Email id verification.. Can anyone tell me how to use this and what is the meaning of this \w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)* this is not really a python question. I would suggest you locate a good regular expression tutorial then try to break it down otherwise you could try asking in an asp.net forum -- Sometimes when presented with a problem you will think I know I will use regular expressions Now you have two problems. -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Thu, May 24, 2012 at 11:45 PM, Dennis Lee Bieber wlfr...@ix.netcom.com wrote: And maybe follow-up with a review of this monster: http://www.ex-parrot.com/pdw/Mail-RFC822-Address.html That is awesome. Epic. Eyeball-bleeding. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On 5/24/2012 5:32 AM, niks wrote: Hello everyone.. I am new to asp.net... I want to use Regular Expression validator in Email id verification.. Can anyone tell me how to use this and what is the meaning of this \w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)* Not a Python question. It matches anything that looks like a mail user name followed by an @ followed by anything that looks more or less like a domain name. The domain name must contain at least one ., and cannot end with a ., which is not strictly correct but usually works. John Nagle -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
John Nagle na...@animats.com writes: It matches anything that looks like a mail user name followed by an @ followed by anything that looks more or less like a domain name. The domain name must contain at least one ., and cannot end with a ., which is not strictly correct but usually works. It will reject many valid email addresses. For better guidance on verifying email address values, see the official recommendations in RFC 3696 URL:https://tools.ietf.org/html/rfc3696. In short: don't bother validating email addresses, the email system is best placed to do that. Just try using them and catch the failures when they happen. -- \ “He was the mildest-mannered man / That ever scuttled ship or | `\ cut a throat.” —“Lord” George Gordon Noel Byron, _Don Juan_ | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On 25May2012 01:20, Chris Angelico ros...@gmail.com wrote: | On Thu, May 24, 2012 at 11:45 PM, Dennis Lee Bieber | wlfr...@ix.netcom.com wrote: | And maybe follow-up with a review of this monster: | http://www.ex-parrot.com/pdw/Mail-RFC822-Address.html | | That is awesome. Epic. Eyeball-bleeding. +1 !! I hope someone's validated that regexp before using it to validate email addresses:-) I'm amazed. (And amazed that the sheer code smell doesn't drive the author away from suggesting it.) The mere presence of nesting comments in RFC2822 addresses prevents using a single regexp to parse them. -- Cameron Simpson c...@zip.com.au DoD#743 http://www.cskk.ezoshosting.com/cs/ It's state-of-the-art But it doesn't work! That is the state-of-the-art. -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On 24May2012 05:32, niks nikunjparmar...@gmail.com wrote: | Hello everyone.. | I am new to asp.net... Time to run away fast before you're commited then:-) You're aware this is a _python_ list/group, yes? | I want to use Regular Expression validator in Email id verification.. You can't. Valid addresses including nesting comments. Regexps don't do recursion. | Can anyone tell me how to use this and what is the meaning of | this | \w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)* If you don't understand it, DON'T use it. And in any case, it is simplistic (== wrong). As pointed out by others in this thread. -- Cameron Simpson c...@zip.com.au DoD#743 http://www.cskk.ezoshosting.com/cs/ Men are four: He who knows and knows that he knows; he is wise, follow him. He who knows and knows not that he knows; he is asleep, wake him. He who knows not and knows that he knows not; he is ignorant, teach him. He who knows not and knows not that he knows not; he is a fool, spurn him! -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Fri, May 25, 2012 at 9:03 AM, Cameron Simpson c...@zip.com.au wrote: On 24May2012 05:32, niks nikunjparmar...@gmail.com wrote: | Hello everyone.. | I am new to asp.net... Time to run away fast before you're commited then:-) You're aware this is a _python_ list/group, yes? Committed to an asylum or to source control? Python is an asylum. Ruled by a Benevolent Inmate For Life. And yes, it's a life sentence. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Thu, 24 May 2012 05:32:16 -0700, niks wrote: Hello everyone.. I am new to asp.net... I want to use Regular Expression validator in Email id verification.. Why do you want to write buggy code that makes your users hate your program? Don't do it! Write good code, useful code! Validating email addresses is the wrong thing to do. The only way to validate an email address is to ACTUALLY SEND AN EMAIL TO IT. That is all. Just because an address is syntactically valid doesn't mean it is deliverable. You can't validate postal addresses. How would you even try? Even if you could, you wouldn't use a regex for it. That's the post office's job to decide whether mail can be delivered, not yours. Who are you to say that some address in Russia or Bolivia or Kuwait is invalid? Email addresses are no different. It is the job of the mail server to decide whether email can be delivered, not yours. http://northernplanets.blogspot.com.au/2007/03/how-not-to-validate-email-addresses.html http://haacked.com/archive/2007/08/21/i-knew-how-to-validate-an-email-address-until-i.aspx http://haacked.com/archive/2007/08/26/dont-be-a-validation-nazi.aspx -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On 25/05/2012 00:03, Cameron Simpson wrote: On 24May2012 05:32, niksnikunjparmar...@gmail.com wrote: | Hello everyone.. | I am new to asp.net... Time to run away fast before you're commited then:-) You're aware this is a _python_ list/group, yes? | I want to use Regular Expression validator in Email id verification.. You can't. Valid addresses including nesting comments. Regexps don't do recursion. Some regex implementations _can_ do recursion. | Can anyone tell me how to use this and what is the meaning of | this | \w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)* If you don't understand it, DON'T use it. And in any case, it is simplistic (== wrong). As pointed out by others in this thread. True, it's the wrong tool for the job. -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
Steven D'Aprano steve+comp.lang.pyt...@pearwood.info writes: Why do you want to write buggy code that makes your users hate your program? ... The only way to validate an email address is to ACTUALLY SEND AN EMAIL TO IT. Of course spamming people will make them hate you even more. Insisting that people give you a valid email address (unless you have a demonstrably legitimate use for it) is a variant of that. -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Thu, 24 May 2012 18:35:21 -0700, Paul Rubin wrote: Steven D'Aprano steve+comp.lang.pyt...@pearwood.info writes: Why do you want to write buggy code that makes your users hate your program? ... The only way to validate an email address is to ACTUALLY SEND AN EMAIL TO IT. Of course spamming people will make them hate you even more. Insisting that people give you a valid email address (unless you have a demonstrably legitimate use for it) is a variant of that. Ha, of course. I assumed that the OP actually has a valid reason for requesting an email address from the user. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
On Fri, May 25, 2012 at 11:35 AM, Paul Rubin no.email@nospam.invalid wrote: Steven D'Aprano steve+comp.lang.pyt...@pearwood.info writes: Why do you want to write buggy code that makes your users hate your program? ... The only way to validate an email address is to ACTUALLY SEND AN EMAIL TO IT. Of course spamming people will make them hate you even more. Insisting that people give you a valid email address (unless you have a demonstrably legitimate use for it) is a variant of that. But why do you want to validate the email address? That's the question. Usually it's because you're going to be sending emails to that address, in which case you not only want to ensure that it's a real address, you want to ensure that the person who keyed it in is legitimately allowed to do so - the usual implementation of that being please check your emails for the confirmation code. There are, however, ways of not-quite-sending an email. For instance, you can connect to the domain's MX, give your HELO, MAIL FROM, and RCPT TO commands, and then quit before sending any DATA. That won't give a 100% guarantee, but it'll certainly tell you about a lot of failures (most of them in that first megastep of looking up the domain in DNS to find its MX record, and then attempting a connection). Now, if your goal is to recognize email addresses in plain text (eg to make them clickable), then you probably don't want true validation - you want more of a DWIM setup where common tails aren't included [for instance, an email address followed by a close bracket, like f...@bar.com]. That's completely different. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
Paul Rubin no.email@nospam.invalid writes: Steven D'Aprano steve+comp.lang.pyt...@pearwood.info writes: Why do you want to write buggy code that makes your users hate your program? ... The only way to validate an email address is to ACTUALLY SEND AN EMAIL TO IT. Of course spamming people will make them hate you even more. Use the email address without spamming, then. The point is that, having collected the email address, it's useless unless one actually uses it *as an email address*, by sending a message to it. Before then, “validating” it tells you nothing. Insisting that people give you a valid email address (unless you have a demonstrably legitimate use for it) is a variant of that. And matching it against a regex is going to either get it wrong (rejecting many valid email addresses), or be useless (accepting just about anything as “valid”). The test which matters is to use the value as an email address, by sending a message when the time comes to do that. -- \ “It's my belief we developed language because of our deep inner | `\ need to complain.” —Jane Wagner, via Lily Tomlin | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: Email Id Verification
Ben Finney ben+pyt...@benfinney.id.au writes: The point is that, having collected the email address, it's useless unless one actually uses it *as an email address*, by sending a message to it. Before then, “validating” it tells you nothing. Right, the only legitimate use of an email address is sending legitimate email to it. An example might be collecting an address so that service staff can respond to a help request. If there is not an up-front, good reason to want to email the address, then collecting it is not legitimate. An example is web sites where users have to supply addresses to register. This is why mailinator.com was invented, but it's annoying even if you use mailinator. -- http://mail.python.org/mailman/listinfo/python-list
