A message you sent could not be delivered to some or all of its recipients. The following addresses were undeliverable: usermail@yahoo.com: Mail from 123.456.789.123 not allowed – 5.7.1 [BL21] Connections not accepted from IP addresses on Spamhaus PBL; see http://postmaster.yahoo.com/errors/550-bl21.html [550] Itu adalah pesan yang muncul ketika email yang dikirimkan dari institusi (mail.say.ac.id) ke mail.yahoo.com […]
