EDIT: This question is pointless, except as an exercise in red herrings. The issue turned out to be a combination of my idiocy (NO ONE was being emailed as the hos
I wasn't able to replicate your bug:
var message = new MailMessage();
message.To.Add("user@example.com");
message.To.Add("user2@example.com");
message.From = new MailAddress("test@example.com");
message.Subject = "Test";
message.Body = "Test";
var client = new SmtpClient("localhost", 25);
client.Send(message);
Dumping the contents of the To: MailAddressCollection:
MailAddressCollection (2 items)
DisplayName User Host Addressuser example.com user@example.com
user2 example.com user2@example.com
And the resulting e-mail as caught by smtp4dev:
Received: from mycomputername (mycomputername [127.0.0.1])
by localhost (Eric Daugherty's C# Email Server)
3/8/2010 12:50:28 PM
MIME-Version: 1.0
From: test@example.com
To: user@example.com, user2@example.com
Date: 8 Mar 2010 12:50:28 -0800
Subject: Test
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: quoted-printable
Test
Are you sure there's not some other issue going on with your code or SMTP server?