Generally not; it usuallly means a domain name on your server is being used by a spammer. The spammer is most likely not on your server; just hijacking a domain name. There's not much you can do except perhaps change defaults in exim.conf so undeliverable emails will be frozen/deleted more quickly than they are now.I have a lot e-mails in mail queue sent from "<>" to all kind of weird e-mail adresses.
Does that mean my mailserver is have been hacked??
how can i check it?and how can i stop it?
This is standard for DirectAdmin mail servers.i want to ask how can i setting just my server and my customer can send mail. the other can't send mail using my smtp?
Generally not; it usuallly means a domain name on your server is being used by a spammer. The spammer is most likely not on your server; just hijacking a domain name. There's not much you can do except perhaps change defaults in exim.conf so undeliverable emails will be frozen/deleted more quickly than they are now.
This is standard for DirectAdmin mail servers.
Jeff
Do you mean that you do not even want your own customers to use your server to send mail?