MailAddress Class

MailAddress Class


Represents the address of an electronic mail sender or recipient.

Namespace:   System.Net.Mail
Assembly:  System (in System.dll)


public class MailAddress


Initializes a new instance of the MailAddress class using the specified address.

System_CAPS_pubmethodMailAddress(String, String)

Initializes a new instance of the MailAddress class using the specified address and display name.

System_CAPS_pubmethodMailAddress(String, String, Encoding)

Initializes a new instance of the MailAddress class using the specified address, display name, and encoding.


Gets the e-mail address specified when this instance was created.


Gets the display name composed from the display name and address information specified when this instance was created.


Gets the host portion of the address specified when this instance was created.


Gets the user information from the address specified when this instance was created.


Compares two mail addresses.(Overrides Object.Equals(Object).)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Returns a hash value for a mail address.(Overrides Object.GetHashCode().)


Gets the Type of the current instance.(Inherited from Object.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Returns a string representation of this instance.(Overrides Object.ToString().)

The MailAddress class is used by the SmtpClient and MailMessage classes to store address information for e-mail messages.

A mail address is composed of a User name, Host name and optionally, a DisplayName. The DisplayName can contain non-ASCII characters if you encode them.

The MailAddress class supports the following mail address formats:

  • A simple address format of user@host. If a DisplayName is not set, this is the mail address format generated.

  • A standard quoted display name format of "display name" <user@host>. If a DisplayName is set, this is the format generated.

  • Angle brackets are added around the User name, Host name for "display name" user@host if these are not included.

  • Quotes are added around the DisplayName for display name <user@host>, if these are not included.

  • Unicode characters are supported in the DisplayName. property.

  • A User name with quotes. For example, "user name"@host.

  • Consecutive and trailing dots in user names. For example,

  • Bracketed domain literals. For example, <user@[my domain]>.

  • Comments. For example, (comment)"display name"(comment)<(comment)user(comment)@(comment)domain(comment)>(comment). Comments are removed before transmission.

A comma is used to separate elements in a list of mail addresses. As a result, a comma should not be used in unquoted display names in a list. The following mail addresses would be allowed

"John, Doe" <user@host>, "Bob, Smith" <user2@host>

The following mail address would not be allowed:

John, Doe <user@host>, Bob, Smith <user2@host>

Quotes can be embedded in a quoted string, but they must be escaped. The following mail addresses would be allowed

"John \"Jr\" Doe" <user@host>

"\"John \\\"Jr\\\" Doe\" <user@host>"

The following mail address would not be allowed:

"John "Jr" Doe" <user@host>

When the username is note quoted, all text between the start of the string (or comma) and the address are considered part of the DisplayName, including comments.

-- Example: (non comment) unquoted display (non comment) name (non comment) <user@host>

Although the MailAddress class accepts a mail address as valid, other mail servers may not accept the mail address.

The MailAddress class does not support the following mail address formats:

Mixed quoted and unquoted display names. For example, display "name" <user@host>

Groups, as defined in RFC 2822 Section 3.4 published by the IETF.

The obsolete user name formats of "user"."name"@host, user."name"@host or "user".name@host

Legacy Code Example

The following code example demonstrates sending an e-mail message by using the SmtpClient, MailAddress, and MailMessage classes.

public static void CreateCopyMessage(string server)
	MailAddress from = new MailAddress("", "Ben Miller");
	MailAddress to = new MailAddress("", "Jane Clayton");
	MailMessage message = new MailMessage(from, to);
	// message.Subject = "Using the SmtpClient class.";
	message.Subject = "Using the SmtpClient class.";
	message.Body = @"Using this feature, you can send an e-mail message from an application very easily.";
	// Add a carbon copy recipient.
	MailAddress copy = new MailAddress("");
	SmtpClient client = new SmtpClient(server);
	// Include credentials if the server requires them.
	client.Credentials = CredentialCache.DefaultNetworkCredentials;
	Console.WriteLine("Sending an e-mail message to {0} by using the SMTP host {1}.",
		 to.Address, client.Host);

   try {
    catch (Exception ex) {
      Console.WriteLine("Exception caught in CreateCopyMessage(): {0}", 
                  ex.ToString() );

.NET Framework
Available since 2.0

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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