Server replied: 550 5.1.1

[valerossi46]

Hi,
I want use my virtual server with ispCP control only for webhosting my sites. I have Emailhosting on the another server.

If I send email from webmail or HTML form in site(php function mail())....I get this notificication "Requested action not taken: mailbox unavailable
Server replied: 550 5.1.1 <info@kovodel.cz>: Recipient address rejected: User unknown in virtual mailbox table"
(this notification is only in webmail, if I send from HTML form then I become nothing)

I have kovodel.cz like user/domain in ispCP Control but I have no emails in this domain. (reason: I have another server for emails)

Is some good solution for my case?

Thx Jiri B.