Question

In reading about what would be the best way to validate a mail address via regular expressions, I came across with an attempt to validate with

try
{
    new MailAddress(input);
}
catch (Exception ex)
{
    // invalid
}

What method does the MailAddress class use to ensure a mail address is valid?

Answer 1

If you mean by validate whether or not it’s a valid e-mail address format, it supports several standard formats:

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” .
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 ,
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,
user…name..@host.

Bracketed domain literals. For example, .

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

.

This is from MailAddress Class

As for what method it uses to validate the formats, I don’t know. You could always try Reflector to see what it’s doing internally. Is there a particular reason you want to know the internal details?