title: Exchange server will not accept username/password provided with javax.mail API
body: <p>I have a lovely little Java client that sends signed email messages. We have an Exchange server that requires username/password authentication to send a message.</p>
  
  <p>When I connect to the exchange server, I get this error:</p>
  
  <pre><code>avax.mail.AuthenticationFailedException: failed to connect
          at javax.mail.Service.connect(Service.java:322)
          at javax.mail.Service.connect(Service.java:172)
  </code></pre>
  
  <p>When I connect to other servers (Unix servers), I have no problem.</p>
  
  <p>Below is the full debug trace. I can't figure it out. </p>
  
  <pre><code>DEBUG: JavaMail version 1.4.2
  DEBUG: successfully loaded resource: /META-INF/javamail.default.providers
  DEBUG: Tables of loaded providers
  DEBUG: Providers Listed By Class Name: {com.sun.mail.smtp.SMTPSSLTransport=javax.mail.Provider[TRANSPORT,smtps,com.sun.mail.smtp.SM}
  DEBUG: Providers Listed By Protocol: {imaps=javax.mail.Provider[STORE,imaps,com.sun.mail.imap.IMAPSSLStore,Sun Microsystems, Inc], }
  DEBUG: successfully loaded resource: /META-INF/javamail.default.address.map
  DEBUG: getProvider() returning javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.smtp.SMTPTransport,Sun Microsystems, Inc]
  DEBUG SMTP: useEhlo true, useAuth true
  DEBUG SMTP: trying to connect to host "SERVER", port 25, isSSL false
  220 SERVER ESMTP (deca81216f2ecf4fd6fedb030e3dcfd0)
  DEBUG SMTP: connected to host "SERVER", port: 25
  
  EHLO CLIENT
  250-SERVER Hello CLIENT [192.1.1.1], pleased to meet you
  250-STARTTLS
  250-PIPELINING
  250-SIZE 100000000
  250-AUTH LOGIN PLAIN
  250-AUTH=LOGIN PLAIN
  250-8BITMIME
  250 HELP
  DEBUG SMTP: Found extension "STARTTLS", arg ""
  DEBUG SMTP: Found extension "PIPELINING", arg ""
  DEBUG SMTP: Found extension "SIZE", arg "100000000"
  DEBUG SMTP: Found extension "AUTH", arg "LOGIN PLAIN"
  DEBUG SMTP: Found extension "AUTH=LOGIN", arg "PLAIN"
  DEBUG SMTP: Found extension "8BITMIME", arg ""
  DEBUG SMTP: Found extension "HELP", arg ""
  STARTTLS
  220 Ready to start TLS
  EHLO CLIENT
  250-SERVER Hello CLIENT [192.1.1.1], pleased to meet you
  250-PIPELINING
  250-SIZE 100000000
  250-AUTH LOGIN PLAIN
  250-AUTH=LOGIN PLAIN
  250-8BITMIME
  250 HELP
  DEBUG SMTP: Found extension "PIPELINING", arg ""
  DEBUG SMTP: Found extension "SIZE", arg "100000000"
  DEBUG SMTP: Found extension "AUTH", arg "LOGIN PLAIN"
  DEBUG SMTP: Found extension "AUTH=LOGIN", arg "PLAIN"
  DEBUG SMTP: Found extension "8BITMIME", arg ""
  DEBUG SMTP: Found extension "HELP", arg ""
  DEBUG SMTP: Attempt to authenticate
  DEBUG SMTP: check mechanisms: LOGIN PLAIN DIGEST-MD5 
  AUTH LOGIN
  334 VXNlcn5hbWU6
  RVJOXHNsK2FyZmlu
  334 UGFzc3dvcmQ6
  UVdFUnF3ZXIxMjM0IUAjJA==
  535 Error: authentication failed
  DEBUG SMTP: useEhlo true, useAuth true
  DEBUG SMTP: trying to connect to host "SERVER", port 25, isSSL false
  220 SERVER ESMTP (deca81216f2ecf4fd6fedb030e3dcfd0)
  DEBUG SMTP: connected to host "SERVER", port: 25
  
  EHLO CLIENT
  250-SERVER Hello CLIENT [192.1.1.1], pleased to meet you
  250-STARTTLS
  250-PIPELINING
  250-SIZE 100000000
  250-AUTH LOGIN PLAIN
  250-AUTH=LOGIN PLAIN
  250-8BITMIME
  250 HELP
  DEBUG SMTP: Found extension "STARTTLS", arg ""
  DEBUG SMTP: Found extension "PIPELINING", arg ""
  DEBUG SMTP: Found extension "SIZE", arg "100000000"
  DEBUG SMTP: Found extension "AUTH", arg "LOGIN PLAIN"
  DEBUG SMTP: Found extension "AUTH=LOGIN", arg "PLAIN"
  DEBUG SMTP: Found extension "8BITMIME", arg ""
  DEBUG SMTP: Found extension "HELP", arg ""
  STARTTLS
  220 Ready to start TLS
  EHLO CLIENT
  250-SERVER Hello CLIENT [192.1.1.1], pleased to meet you
  250-PIPELINING
  250-SIZE 100000000
  250-AUTH LOGIN PLAIN
  250-AUTH=LOGIN PLAIN
  250-8BITMIME
  250 HELP
  DEBUG SMTP: Found extension "PIPELINING", arg ""
  DEBUG SMTP: Found extension "SIZE", arg "100000000"
  DEBUG SMTP: Found extension "AUTH", arg "LOGIN PLAIN"
  DEBUG SMTP: Found extension "AUTH=LOGIN", arg "PLAIN"
  DEBUG SMTP: Found extension "8BITMIME", arg ""
  DEBUG SMTP: Found extension "HELP", arg ""
  DEBUG SMTP: Attempt to authenticate
  DEBUG SMTP: check mechanisms: LOGIN PLAIN DIGEST-MD5 
  AUTH LOGIN
  334 VXNlcm5hbWU6
  RVJOXHNsZ2FyZmlu
  334 UGFzc3dvcmQ6
  UVdFUnF3ZXIxMjM0IUAjJA==
  535 Error: authentication failed
  Error sending mail: failed to connect
  javax.mail.AuthenticationFailedException: failed to connect
          at javax.mail.Service.connect(Service.java:322)
          at javax.mail.Service.connect(Service.java:172)
          at SignMessage.sendSigned(SignMessage.java:248)
          at SignMessage.main(SignMessage.java:340
  </code></pre>