Hi, i use to receive emails before, but recently, when anyone send a mail to me they get the message below. The address is valid, because i used it to send the mails.
Please have a look at for me
A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed:
host xxxinternational.com [xxx]
SMTP error from remote mail server after RCPT TO:<firstname.lastname@example.org>:
550-Please turn on SMTP Authentication in your mail client. ns71.webhostsg.com
550-(web107.webhostsg.com) [xxx]:xxx is not permitted to relay
550 through this server without authentication.