java - Log4j Does not Send Mail unless Thread.sleep -

i having problem log4j , sending notification emails.

my log4j.properties

log4j.appender.mail=org.apache.log4j.net.smtpappender log4j.appender.mail.threshold=error log4j.appender.mail.buffersize=512 log4j.appender.mail.smtphost=10.10.10.10 log4j.appender.mail.from=team@domain.com log4j.appender.mail.subject=subject here log4j.appender.mail.to=team@domain.com log4j.appender.mail.layout=org.apache.log4j.patternlayout log4j.appender.mail.layout.conversionpattern=%d{yyyy/mm/dd hh:mm:ss,sss} [%t] %-5p %c %x - %m%n 

the program caused error when trying send , email made log.error() test it.

i tested code below, still did not send emails.

public static void main(string[] args) {     log.error("error "); } 

when add thread.sleep in above code. works!

public static void main(string[] args) throws exception{     log.error("error ");     thread.sleep(1000000l); } 

the problem main thread exits , causes mail sending thread terminate. decided change program wait(not exit) until log4j sending mails completely. have no idea how mail-sending status in log4j.

any appreciate.

try set buffersize value 1, maybe logger waiting full buffer before sending