smtp.Sendmail fails after 10 minutes with EOF
===

I'm trying to send mail via the standard library SMTP package and it does nothing for exactly 10 minutes and then fails with an unhelpful End of File error I can't make sense of.

    
    // excerpt from the calling function
    // --- snip ---
    if e := mailNotify(board, validPosts, ipMinusPort, delTime); e != nil {
        errorPage(w, tmpl, "Contact Administrator",
            "Email notification failed, please contact archive admin.")
        log.Println("ERROR: Failed to send notification email: " + e.Error())
    }
    // --- snip ---

    func mailNotify(board *config.Board, validPosts []int64, 
                            ip string, delTime time.Time) error {
    
        addresses := strings.Split(board.NotifyAddr, ",")
        if len(addresses) < 1 {
            return nil
        }
    
        msg := new(bytes.Buffer)
        type values struct {
            IP      string
            Posts   []int64
            DelTime time.Time
        }
        t.ExecuteTemplate(msg, "post_reported", &values{ip, validPosts, delTime})
        auth:= smtp.PlainAuth("", board.NotifyAddr, board.NotifyPass,
            strings.Split(board.SMTPServer, ":")[0])
        return smtp.SendMail(board.SMTPServer, auth,
            board.FromEmail, addresses, msg.Bytes())
    }

The exact message that gets logged is:

> 2012/07/25 22:57:58 ERROR: Failed to send notification email: EOF

I've `log.Printf` debugged this function and verified the values being sent at this point are valid. The email address is a real address on gmail.com and the password is correct, and `board.SMTPServer` is `smtp.googlemail.com:465`. I've tried storing the result of msg.Bytes() in a separate variable and taking the length to be sure that it was producing an byte array to send, and the length is indeed non-zero. I'm guessing the EOF is bubbling up from somwhere deeper in the standard library than the SendMail function itself, but I have no idea where it's choking and I don't know what I did to upset it.