javamail - java mail store type "imap" vs "imaps" -

i using following code validate email programatically.

properties properties = new properties(); session emailsession = session.getdefaultinstance(properties); store store = emailsession.getstore("imap");  store.connect(host, user, password); if(store.isconnected()){       system.out.println("true");  } 

currently throws exception

javax.mail.messagingexception: connection dropped server?; nested exception is: java.io.ioexception: connection dropped server? @ com.sun.mail.imap.imapstore.protocolconnect(imapstore.java:670) @ javax.mail.service.connect(service.java:295) @ javax.mail.service.connect(service.java:176) @ com.**.channel.type.imapvalidator.fetch(imapvalidator.java:23) @ com.**.channel.type.imapvalidator.main(imapvalidator.java:47) 

however if use

emailsession.getstore("imaps"); 

then connects imap server of yahoo.

what know "imaps" stands "secure".

what dont know why cant use "imap"?

google require secure connection.

https://support.google.com/mail/troubleshooter/1668960?hl=en#ts=1665018%2c1665144