Undeliverable mail to my server - but only from some ISP's
my server is running fine for just about everybody, but there are two individuals who say they can send emails to anyone they like, unless their mailbox is on my server. If they try sending to an email address on my server then they get bounced.
I have hundreds of others happily sending emails to hundreds of mailboxes on my server though, so I really dont know what is going on.
Any ideas?
