what would be my imap.conf configuration ?

[JOYDEEP]

Dear list,

it has now cleared to me   If no MX is found for domain, the MTA will
sent the mail to the resolving host.
In this way a no. of mail system is working. now I also have a domain
which is pointing to my remote root server.
say it is mydomain.com   So how can I use this domain to get mail for
user at mydomain.com 
here is my /etc/imapd.conf which I configured for dedicated.hosteurope.de
-----------------------------------------------------
configdirectory: /var/lib/imap
partition-default: /var/spool/imap
sievedir: /var/lib/sieve

admins: cyrus
allowanonymouslogin: no
allowplaintext: yes
sasl_pwcheck_method: saslauthd
sasl_mech_list: PLAIN LOGIN
sasl_minimum_layer: 0

autocreatequota: 10000
reject8bit: no
quotawarn: 90
timeout: 30
poptimeout: 10
dracinterval: 0
drachost: localhost

servername: lvps87-230-8-228.dedicated.hosteurope.de
defaultdomain: dedicated.hosteurope.de
loginrealms:  dedicated.hosteurope.de

unixhierarchysep:  no
virtdomains:       yes
hashimapspool: true

lmtp_overquota_perm_failure: no
lmtp_downcase_rcpt: yes
lmtpsocket:  /var/lib/imap/socket/lmtp

tls_ca_file:      /var/myca/demoCA/cacert.pem
tls_cert_file:    /var/myca/newcert.pem
tls_key_file:     /var/myca/newreq.pem
--------------------------------------------------------