Of course, you can block hostnames if they can be resolved via DNS. You can
use acls like this:
acl_check_coonect:
deny message = This hostname is blocked
condition = ${if eq{$sender_host_name}{some.hostname.com} {yes}
{no}}
If you have several host names to block, you can use lists and lookups instead
of if condition. See exim documentation
Exim_User:
> Hi,
>
> Is there any way that i can block particular hostname from sending the
> mail.... as my server is getting hit from a common host name but thousands
> of Ip's
>
> Rahul