BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Validate an email address          BorlandTalk.com Forum Index -> C++ Builder (Internet Web) View previous topic :: View next topic   Author Message Mark Jacobs Guest Posted: Mon May 22, 2006 1:14 pm    Post subject: Validate an email address How do I go about validating both the username and domain name parts of an email address? For example (*not* real addresses) :- hilary.jenkins (AT) grossfahrt (DOT) com is valid henry.johnson (AT) grossfahrt (DOT) com is invalid hilary.jenkins (AT) grobfahrt (DOT) com is valid TIA, -- · Mark Jacobs DK Computing http://www.dkcomputing.co.uk Back to top Hans Galema Guest Posted: Mon May 22, 2006 5:14 pm    Post subject: Re: Validate an email address Mark Jacobs wrote: Quote: hilary.jenkins (AT) grossfahrt (DOT) com is valid henry.johnson (AT) grossfahrt (DOT) com is invalid hilary.jenkins (AT) grobfahrt (DOT) com is valid Why would the second one be invalid ? They all have the same syntax. Or do you mean non existing ? Hans. Back to top Remy Lebeau (TeamB) Guest Posted: Mon May 22, 2006 6:17 pm    Post subject: Re: Validate an email address "Mark Jacobs" <http://www.jacobsm.com/mjmsg?Borland%20Newsgroup> wrote in message news:4471afcd$1 (AT) newsgroups (DOT) borland.com... Quote: How do I go about validating both the username and domain name parts of an email address? You would have to use a DNS lookup to get the MX records of the domain. The MX records contain the IP addresses of the domain's SMTP servers. You would then have to connect to each server, issuing a VRFY command to each one, until one of them reports success. Do note, however, that some servers dsable the VRFY command, unfortunately. Gambit Back to top Remy Lebeau (TeamB) Guest Posted: Mon May 22, 2006 10:14 pm    Post subject: Re: Validate an email address "Mark Jacobs" <www.jacobsm.com/mjmsg.htm?Borland Newsgroup> wrote in message news:447230b2$1 (AT) newsgroups (DOT) borland.com... Quote: I found out that our server does not support the VRFY command Then you wil not be able to verify users on your own server. Quote: I'm wondering what proportion of SMTP servers do? That number is decreasing, unfortunately. As spamming and abusing increasing, more and more system admins are closing down the features that allowed them to do their malicious work, and are implementing tighter security and validating protocols. Quote: I also note that some act as relays to *any* request from anywhere (I won't publish the host of one in particular ). A lot of servers don't support relaying anymore, either. It makes it harder for recipient servers to validate the senders. Quote: there is still no guaranteed way of validating an email address Nope, unfortunately. Gambit Back to top Mark Jacobs Guest Posted: Mon May 22, 2006 10:14 pm    Post subject: Re: Validate an email address Remy Lebeau (TeamB) wrote: Quote: "Mark Jacobs" <http://www.jacobsm.com/mjmsg?Borland%20Newsgroup wrote in message news:4471afcd$1 (AT) newsgroups (DOT) borland.com... How do I go about validating both the username and domain name parts of an email address? You would have to use a DNS lookup to get the MX records of the domain. The MX records contain the IP addresses of the domain's SMTP servers. You would then have to connect to each server, issuing a VRFY command to each one, until one of them reports success. Do note, however, that some servers dsable the VRFY command, unfortunately. Thanks. I found out that our server does not support the VRFY command, and I'm wondering what proportion of SMTP servers do? I also note that some act as relays to *any* request from anywhere (I won't publish the host of one in particular ). In my experience, there is still no guaranteed way of validating an email address, because, just this luch-time, the DNS server was timing out, as our execs played a LAN shoot 'em up! That's difficult to program for, unless you know their "timetable" in advance. -- Mark Jacobs http://jacobsm.com Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> C++ Builder (Internet Web) All times are GMT Page 1 of 1   Jump to: Select a forum C++ Builder Newsgroups----------------C++ BuilderC++ Builder (ActiveX)C++ Builder (Announcements)C++ Builder (Command Line Tools)C++ Builder DatabasesC++ Builder Databases (ADO)C++ Builder Databases (Desktop)C++ Builder Databases (InterBase Express)C++ Builder Databases (Multi-Tier)C++ Builder Databases (SQL Servers)C++ Builder (Graphics)C++ Builder (IDE)C++ Builder (Internet)C++ Builder (Internet Socket)C++ Builder (Internet Web)C++ Builder (Jobs)C++ Builder (Language)C++ Builder (Language C++)C++ Builder (Compatibility with MFC)C++ Builder (Native API)C++ Builder (Non-Technical)C++ Builder (Students)C++ Builder (Third Party Tools)C++ Builder (Upgrade)C++ Builder (VCL)C++ Builder (VCL Components Usage)C++ Builder (VCL Components Development)C++ Builder (VCL Usage)C++ Builder (WinAPI)C++ Builder Installation Delphi Newsgroups----------------Delphi (General)Delphi ActiveX Controls UsageDelphi ActiveX Controls DevelopmentDelphi As400Delphi DatabasesDelphi Databases (ADO)Delphi Databases (dbExpress)Delphi Databases (Desktop)Delphi Databases (InterBase Express)Delphi Databases (Multi-Tier)Delphi Databases (SQL Servers)Delphi DeploymentDelphi GraphicsDelphi IDEDelphi InternationalizationDelphi InternetDelphi Internet Isapi-WebBrokerDelphi Internet WebSnapDelphi Internet WinsockDelphi JobsDelphi Language BASMDelphi Language ObjectPascalDelphi Model Driven Architecture (General)Delphi Model Driven Architecture (Third Party)Delphi MultimediaDelphi Native APIDelphi Non-TechnicalDelphi ObjectPascalDelphi OLE AutomationDelphi OO designDelphi OpenToolsAPIDelphi Reporting-ChartingDelphi RTLDelphi StudentsDelphi TeamSourceDelphi Thirdparty ToolsDelphi Thirdparty Tools (General)Delphi Thirdparty Tools (IntraWeb)Delphi Thirdparty Tools (RaveReports)Delphi UpgradeDelphi VCLDelphi VCL ComponentsDelphi VCL Components UsingDelphi VCL Components WritingDelphi WebServices SOAPDelphi WinAPIDelphi XMLDelphi Installationcomp.lang.pascal.delphi.components.misccomp.lang.pascal.delphi.components.usagecomp.lang.pascal.delphi.components.writingcomp.lang.pascal.delphi.databasescomp.lang.pascal.delphi.misccomp.sources.delphi JBuilder Newsgroups----------------JBuilderJBuilder AnnouncementsJBuilder Applet IssuesJBuilder As400JBuilder CompilerJBuilder CORBA/RMIJBuilder DatabasesJBuilder DB SwingJBuilder DebuggerJBuilder DeploymentJBuilder DocumentationJBuilder EnterpriseJBuilder HandheldJBuilder IDEJBuilder JavaJBuilder JavaAPIJBuilder Java LanguageJBuilder Java SwingJBuilder Java BeansJBuilder Java Beans UsageJBuilder Java Beans DevelopmentJBuilder JBCLJBuilder JDataStoreJBuilder JobsJBuilder LinuxJBuilder MacintoshJBuilder & MobileSetJBuilder MultiLingual AppsJBuilder Non-TechnicalJBuilder OpenToolsJBuilder Servlets (JSP)JBuilder StudentsJBuilder Team DevelopmentJBuilder Thirdparty ToolsJBuilder UpgradeJBuilder Installation InterBase Newsgroups----------------InterBaseInterBase Bug DiscussionInterBase GeneralInterBase IBConsoleInterBase OpenSourceInterBase ReplicationInterBase SQLInterBase ThirdpartyInterBase Installation Miscellaneous Borland Newsgroups----------------AppCenterAppServerEnteraVisiBroker  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.