[GELÖST] "User unknown in virtual alias table" - Nur bei einer Domain

Code:
alias_database = hash:/etc/aliases

alias_maps = hash:/etc/aliases

append_at_myorigin = yes

append_dot_mydomain = no

biff = no

broken_sasl_auth_clients = yes

command_directory = /usr/sbin

config_directory = /etc/postfix

daemon_directory = /usr/lib/postfix

inet_interfaces = all

local_destination_recipient_limit = 1

local_recipient_maps = unix:passwd.byname $alias_maps

local_transport = local

mail_spool_directory = /var/mail

mailbox_command = procmail -a "$EXTENSION"

mailbox_size_limit = 0

message_size_limit = 0

mydestination = $mydomain

mydomain = domain1.de

myhostname = $mydomain

mynetworks_style = host

myorigin = $mydomain

owner_request_special = no

recipient_delimiter = +

setgid_group = postdrop

smtpd_banner = SMTP - Say Good bye

smtpd_data_restrictions = reject_multi_recipient_bounce, reject_unauth_pipelining

smtpd_helo_required = yes

smtpd_helo_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_invalid_helo_hostname, reject_non_fqdn_helo_hostname

smtpd_recipient_restrictions = reject_non_fqdn_recipient, reject_unknown_recipient_domain, permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, reject_unlisted_recipient, check_policy_service inet:127.0.0.1:12525, check_policy_service inet:127.0.0.1:60000, permit

smtpd_sasl_auth_enable = yes

smtpd_sasl_local_domain =

smtpd_sasl_security_options = noanonymous

smtpd_sender_restrictions = reject_non_fqdn_sender, reject_unknown_sender_domain, permit_mynetworks, permit_sasl_authenticated

transport_maps = hash:/etc/postfix/ispcp/transport

unknown_local_recipient_reject_code = 550

virtual_alias_maps = hash:/etc/postfix/ispcp/aliases, hash:/etc/postfix/virtual

virtual_gid_maps = static:8

virtual_mailbox_base = /var/mail/virtual

virtual_mailbox_domains = hash:/etc/postfix/ispcp/domains

virtual_mailbox_limit = 0

virtual_mailbox_maps = hash:/etc/postfix/ispcp/mailboxes

virtual_minimum_uid = 1000

virtual_transport = virtual

virtual_uid_maps = static:1000