I use this
@\"^([\\w\\.\\-]+)@([\\w\\-]+)((\\.(\\w){2,3})+)$\"
regexp to validate the email
([\\w\\.\\-]+)
- this is f
Why not use EF6 attribute based e-mail validation?
As you can see above, Regex validation for e-mail always has some hole in it. If you are using EF6 data annotations, you can easily achieve reliable and stronger e-mail validation with EmailAddress data annotation attribute available for that. I had to remove the regex validation I used before for e-mail when I got mobile device specific regex failure on e-mail input field. When the data annotation attribute used for e-mail validation, the issue on mobile was resolved.
public class LoginViewModel
{
[EmailAddress(ErrorMessage = "The email format is not valid")]
public string Email{ get; set; }
This one prevents invalid emails mentioned by others in the comments:
Abc.@example.com
Abc..123@example.com
name@hotmail
toms.email.@gmail.com
test@-online.com
It also prevents emails with double dots:
hello..world@example..com
Try testing it with as many invalid email addresses as you can find.
using System.Text.RegularExpressions;
public static bool IsValidEmail(string email)
{
return Regex.IsMatch(email, @"\A[a-z0-9]+([-._][a-z0-9]+)*@([a-z0-9]+(-[a-z0-9]+)*\.)+[a-z]{2,4}\z")
&& Regex.IsMatch(email, @"^(?=.{1,64}@.{4,64}$)(?=.{6,100}$).*");
}
See validate email address using regular expression in C#.
1
^[\w!#$%&'*+\-/=?\^_`{|}~]+(\.[\w!#$%&'*+\-/=?\^_`{|}~]+)*@((([\-\w]+\.)+[a-zA-Z]{2,4})|(([0-9]{1,3}\.){3}[0-9]{1,3}))$
2
^(([^<>()[\]\\.,;:\s@\""]+(\.[^<>()[\]\\.,;:\s@\""]+)*)|(\"".+\""))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$
Regex Email Pattern:
^(?:[\\w\\!\\#\\$\\%\\&\\'\\*\\+\\-\\/\\=\\?\\^\\`\\{\\|\\}\\~]+\\.)*[\\w\\!\\#\\$\\%\\&\\'\\*\\+\\-\\/\\=\\?\\^\\`\\{\\|\\}\\~]+@(?:(?:(?:[a-zA-Z0-9](?:[a-zA-Z0-9\\-](?!\\.)){0,61}[a-zA-Z0-9]?\\.)+[a-zA-Z0-9](?:[a-zA-Z0-9\\-](?!$)){0,61}[a-zA-Z0-9]?)|(?:\\[(?:(?:[01]?\\d{1,2}|2[0-4]\\d|25[0-5])\\.){3}(?:[01]?\\d{1,2}|2[0-4]\\d|25[0-5])\\]))$
It has taken many attempts to create an email validator which catches nearly all worldwide requirements for email.
Extension method you can call with:
myEmailString.IsValidEmailAddress();
Regex pattern string you can get by calling:
var myPattern = Regex.EmailPattern;
The Code (mostly comments):
/// <summary>
/// Validates the string is an Email Address...
/// </summary>
/// <param name="emailAddress"></param>
/// <returns>bool</returns>
public static bool IsValidEmailAddress(this string emailAddress)
{
var valid = true;
var isnotblank = false;
var email = emailAddress.Trim();
if (email.Length > 0)
{
// Email Address Cannot start with period.
// Name portion must be at least one character
// In the Name, valid characters are: a-z 0-9 ! # _ % & ' " = ` { } ~ - + * ? ^ | / $
// Cannot have period immediately before @ sign.
// Cannot have two @ symbols
// In the domain, valid characters are: a-z 0-9 - .
// Domain cannot start with a period or dash
// Domain name must be 2 characters.. not more than 256 characters
// Domain cannot end with a period or dash.
// Domain must contain a period
isnotblank = true;
valid = Regex.IsMatch(email, Regex.EmailPattern, RegexOptions.IgnoreCase) &&
!email.StartsWith("-") &&
!email.StartsWith(".") &&
!email.EndsWith(".") &&
!email.Contains("..") &&
!email.Contains(".@") &&
!email.Contains("@.");
}
return (valid && isnotblank);
}
/// <summary>
/// Validates the string is an Email Address or a delimited string of email addresses...
/// </summary>
/// <param name="emailAddress"></param>
/// <returns>bool</returns>
public static bool IsValidEmailAddressDelimitedList(this string emailAddress, char delimiter = ';')
{
var valid = true;
var isnotblank = false;
string[] emails = emailAddress.Split(delimiter);
foreach (string e in emails)
{
var email = e.Trim();
if (email.Length > 0 && valid) // if valid == false, no reason to continue checking
{
isnotblank = true;
if (!email.IsValidEmailAddress())
{
valid = false;
}
}
}
return (valid && isnotblank);
}
public class Regex
{
/// <summary>
/// Set of Unicode Characters currently supported in the application for email, etc.
/// </summary>
public static readonly string UnicodeCharacters = "À-ÿ\p{L}\p{M}ÀàÂâÆæÇçÈèÉéÊêËëÎîÏïÔôŒœÙùÛûÜü«»€₣äÄöÖüÜß"; // German and French
/// <summary>
/// Set of Symbol Characters currently supported in the application for email, etc.
/// Needed if a client side validator is being used.
/// Not needed if validation is done server side.
/// The difference is due to subtle differences in Regex engines.
/// </summary>
public static readonly string SymbolCharacters = @"!#%&'""=`{}~\.\-\+\*\?\^\|\/\$";
/// <summary>
/// Regular Expression string pattern used to match an email address.
/// The following characters will be supported anywhere in the email address:
/// ÀàÂâÆæÇçÈèÉéÊêËëÎîÏïÔôŒœÙùÛûÜü«»€₣äÄöÖüÜß[a - z][A - Z][0 - 9] _
/// The following symbols will be supported in the first part of the email address(before the @ symbol):
/// !#%&'"=`{}~.-+*?^|\/$
/// Emails cannot start or end with periods,dashes or @.
/// Emails cannot have two @ symbols.
/// Emails must have an @ symbol followed later by a period.
/// Emails cannot have a period before or after the @ symbol.
/// </summary>
public static readonly string EmailPattern = String.Format(
@"^([\w{0}{2}])+@{1}[\w{0}]+([-.][\w{0}]+)*\.[\w{0}]+([-.][\w{0}]+)*$", // @"^[{0}\w]+([-+.'][{0}\w]+)*@[{0}\w]+([-.][{0}\w]+)*\.[{0}\w]+([-.][{0}\w]+)*$",
UnicodeCharacters,
"{1}",
SymbolCharacters
);
}
Just let me know IF it doesn't work :)
public static bool isValidEmail(this string email)
{
string[] mail = email.Split(new string[] { "@" }, StringSplitOptions.None);
if (mail.Length != 2)
return false;
//check part before ...@
if (mail[0].Length < 1)
return false;
System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex(@"^[a-zA-Z0-9_\-\.]+$");
if (!regex.IsMatch(mail[0]))
return false;
//check part after @...
string[] domain = mail[1].Split(new string[] { "." }, StringSplitOptions.None);
if (domain.Length < 2)
return false;
regex = new System.Text.RegularExpressions.Regex(@"^[a-zA-Z0-9_\-]+$");
foreach (string d in domain)
{
if (!regex.IsMatch(d))
return false;
}
//get TLD
if (domain[domain.Length - 1].Length < 2)
return false;
return true;
}