def props = new Properties()
props.put 'mail.store.protocol', 'imaps'

def host = 'imap.yandex.ru'
def port = 993
def username = 'username'
def password = 'password'

def store = Session.getDefaultInstance(props, null).store

store.connect(host, port, username, password)

def inbox = store.getFolder('Inbox')

inbox.open(Folder.READ_ONLY)

def messages = inbox.messages

messages.each { Message message ->
    def from = message.getFrom().collect {javax.mail.Address address ->
        if (address instanceof InternetAddress)
            address.address
        else
            address.toString()
    }.join(';')
    def subject = message.subject
    println "$from\t$subject"
}