Some of them worked, some of them didn't work that well. If this method is passed an invalid email address, it will simply throw an error which you can use to your advantage.
I recently discovered a little trick that you can use to validate email addresses, and best of all - it uses a built-in . In the code above, I have created a simple method that passes an email address to the Mail Address class.
Next, it tries to contact the mail exchanger responsible for the given email address and begins a fake SMTP dialog with that server, emulating a real mail server.
Validating email addresses in vb net
Then it extracts the domain from each address and performs different DNS lookups to ensure that the related domain exists and is configured to accept email messages.
After that, it checks an embedded database to find if that domain is a disposable email address (DEA) provider and reacts accordingly.
Option Explicit Public EMsg As String 'used to return potential error messages in the functions below Public Function Validate Email(By Val str Email As String) As Boolean Dim str Tmp As String, n As Long, s EXT As String EMsg = "" 'reset on open for good form Validate Email = True 'Assume true on init s EXT = str Email Do While In Str(1, s EXT, ".") 0 s EXT = Right(s EXT, Len(s EXT) - In Str(1, s EXT, ".")) Loop If str Email = "" Then Validate Email = False EMsg = EMsg & "You did not enter an email address!
" Else If In Str(1, str Email, "@") = 0 Then Validate Email = False EMsg = EMsg & "Your email address does not contain an @ sign." Else If In Str(1, str Email, "@") = 1 Then Validate Email = False EMsg = EMsg & "Your @ sign can not be the first character in your email address!
Furthermore, the component is set to use a particular DNS server (instead of a system-configured server) for its lookups: var settings = new Verification Settings ; // The component will use just the provided DNS server for its lookups settings. thus respecting Netiquette and avoiding being tagged as a spammer by the external mail exchangers: var group = new Verification Group(); // Add some entries to the verification group group = new Verification("[email protected]"); group = new Verification("[email protected]"); // One entry also has non-default settings group = new Verification("[email protected]", new Verification Settings ); // Start the validation of the whole group, asynchronously await engine. Smtp); // At this point, every address has been validated...
Finally, like as in the single validation scenario described above, the component exposes different events that notify the user about changes in the life cycle of each group of validations and their related tasks. NET employs DNS and SMTP protocol functionalities to perform e-mail address validations and absolutely avoids sending any email message to external mail exchangers for delivery. NET verifies email addresses with up to six different kinds of tools.
Email address validation can be tricky at the best of times and with international domain names in email addresses, almost anything is possible.
In my opinion, there is no 100% reliable way of validating email addresses, you just have to make sure that it conforms to as reasonable a standard as possible.
"End If End Function So this part looks for the @ on the first place of the string if the string is in the format @somthing then its not valide so that the funtion calls the goto funtion and moves to Not Valide Next Part like you see is This is a easy if stament we use the instr funtion to make a bool statment dont know the right word for it in english hope you know what i mean so if the instr funtion returns false we know that the @ is missing and this is again not a valide email address and we then call a msgbox to tell that the @ is missing Next Part is This is again a bool statment that looks for what the funtion returns if instr funtion returns false we know that a .