Problem with Spring Security UI

[Nweike]

I am using Spring Security UI Plugin for Grails 2.3.4 . I noticed that when i tried to implement the registration of new user, i get the following error:
+++++++++++++++
java.net.ConnectException: connect: Address is invalid on local machine, or port is not valid on remote machine
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:579)
at java.net.Socket.connect(Socket.java:528)
at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:284)
at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:227)
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1672)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:525)
at javax.mail.Service.connect(Service.java:291)
at grails.plugin.mail.MailMessageBuilder.sendMessage(MailMessageBuilder.groovy:104)
at grails.plugin.mail.MailService.sendMail(MailService.groovy:41)
++++++++++++++++++++++++++

My MailMessageBuilder with line 104 is this
mailSender.send(message instanceof MimeMailMessage ? message.mimeMessage : message)

Pls what am I doing wrong?