Why does gmail close my connection when I send email through Javamail

I have a process (Message Driven Bean) that sends emails every time it gets a message. Emails per message are less than 10. I open 1 connection to my gmail account and send all开发者_StackOverflow社区 emails over that one connection. Every now and then, I get an Exception on Transport.send()

    javax.mail.MessagingException: Can't send command to SMTP host; nested exception is:    
    java.net.SocketException: Connection closed by remote host at
    com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:1878) at 
    com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:1865) at 
    com.sun.mail.smtp.SMTPTransport.close(SMTPTransport.java:973) at 
    javax.mail.Transport.send0(Transport.java:193) at 
    javax.mail.Transport.send(Transport.java:120) at 
....

Is gmail closing the connection because it thinks that it is spam? I know there is a limitation on number of cocurrent connections to gmail (10) but this seems different. Would using a connection pool help?

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Either Gmail time out on your TCP/IP connection and decides to close it, or a firewall in between detects the connection to be idle and closes it.