OS: CentOS 7

Here's log:

Mar 6 17:37:43 mail postfix/qmgr[13693]: D5551AD26F: from=<account@gmail.com>, size=3302, nrcpt=1 (queue active)
Mar 6 17:37:43 mail postfix/error[14490]: D5551AD26F: to=<user@domain.com>, relay=none, delay=0.31, delays=0.27/0.02/0/0.02, dsn=5.1.1, status=bounced (User unknown in virtual alias table)

postconf -n :

postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_sender_restrictions
postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_client_restrictions
postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_helo_restrictions
postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_sender_restrictions
postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_client_restrictions
postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_helo_restrictions
postconf: warning: /etc/postfix/main.cf: undefined parameter: virtual_mailbox_limit_maps
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
broken_sasl_auth_clients = yes
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
debug_peer_level = 2
debug_peer_list = domain.com
debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin ddd $daemon_directory/$process_name $process_id & sleep 5
dovecot_destination_recipient_limit = 1
home_mailbox = Maildir/
html_directory = no
inet_interfaces = all
inet_protocols = all
local_recipient_maps = proxy:mysql:/etc/postfix/mysql-alias.cf
mail_owner = postfix
mailbox_command = /usr/lib/dovecot/deliver
mailbox_size_limit = 22226666666
mailbox_transport = lmtp:unix:/var/spool/postfix/private/dovecot-lmtp
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
message_size_limit = 21474836480
mydestination = $myhostname, localhost.$mydomain, localhost
mydomain = domain.com
myhostname = mail.domain.com
myorigin = $mydomain
newaliases_path = /usr/bin/newaliases.postfix
proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks $virtual_mailbox_limit_maps
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-2.10.1/README_FILES
relay_domains = *
sample_directory = /usr/share/doc/postfix-2.10.1/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtp_tls_note_starttls_offer = yes
smtp_tls_security_level = may
smtpd_banner = $myhostname ESMTP $mail_name
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, permit
smtpd_sasl_auth_enable = yes
smtpd_sasl_authenticated_header = yes
smtpd_sasl_local_domain =
smtpd_sasl_path = private/auth
smtpd_sasl_security_options = noanonymous
smtpd_sasl_type = dovecot
smtpd_tls_cert_file = /etc/letsencrypt/live/mail.domain.com/fullchain.pem
smtpd_tls_key_file = /etc/letsencrypt/live/mail.domain.com/privkey.pem
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_security_level = may
smtpd_tls_session_cache_timeout = 3600s
smtpd_use_tls = yes
tls_random_source = dev:/dev/urandom
unknown_local_recipient_reject_code = 550
virtual_alias_domains = mysql:/etc/postfix/mysql-domains.cf
virtual_alias_maps = mysql:/etc/postfix/mysql-alias.cf
virtual_gid_maps = static:5000
virtual_mailbox_base = /home/vmail
virtual_mailbox_maps = mysql:/etc/postfix/mysql-users.cf
virtual_transport = lmtp:unixrivate/dovecot-lmtp
virtual_uid_maps = static:5000


doveconf -n :


postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_sender_restrictions
postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_client_restrictions
postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_helo_restrictions
postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_sender_restrictions
postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_client_restrictions
postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_helo_restrictions
postconf: warning: /etc/postfix/main.cf: undefined parameter: virtual_mailbox_limit_maps
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
broken_sasl_auth_clients = yes
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
debug_peer_level = 2
debug_peer_list = domain.com
debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin ddd $daemon_directory/$process_name $process_id & sleep 5
dovecot_destination_recipient_limit = 1
home_mailbox = Maildir/
html_directory = no
inet_interfaces = all
inet_protocols = all
local_recipient_maps = proxy:mysql:/etc/postfix/mysql-alias.cf
mail_owner = postfix
mailbox_command = /usr/lib/dovecot/deliver
mailbox_size_limit = 22226666666
mailbox_transport = lmtp:unix:/var/spool/postfix/private/dovecot-lmtp
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
message_size_limit = 21474836480
mydestination = $myhostname, localhost.$mydomain, localhost
mydomain = domain.com
myhostname = mail.domain.com
myorigin = $mydomain
newaliases_path = /usr/bin/newaliases.postfix
proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domaial_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks $virtual_mailbox_limit_maps
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-2.10.1/README_FILES
relay_domains = *
sample_directory = /usr/share/doc/postfix-2.10.1/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtp_tls_note_starttls_offer = yes
smtp_tls_security_level = may
smtpd_banner = $myhostname ESMTP $mail_name
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, permit
smtpd_sasl_auth_enable = yes
smtpd_sasl_authenticated_header = yes
smtpd_sasl_local_domain =
smtpd_sasl_path = private/auth
smtpd_sasl_security_options = noanonymous
smtpd_sasl_type = dovecot
smtpd_tls_cert_file = /etc/letsencrypt/live/mail.domain.com/fullchain.pem
smtpd_tls_key_file = /etc/letsencrypt/live/mail.domain.com/privkey.pem
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_security_level = may
smtpd_tls_session_cache_timeout = 3600s
smtpd_use_tls = yes
tls_random_source = dev:/dev/urandom
unknown_local_recipient_reject_code = 550
virtual_alias_domains = mysql:/etc/postfix/mysql-domains.cf
virtual_alias_maps = mysql:/etc/postfix/mysql-alias.cf
virtual_gid_maps = static:5000
virtual_mailbox_base = /home/vmail
virtual_mailbox_maps = mysql:/etc/postfix/mysql-users.cf
virtual_transport = lmtp:unixrivate/dovecot-lmtp
virtual_uid_maps = static:5000
[root@mail postfix]# ^C
[root@mail postfix]# doveconf -n
# 2.2.36 (1f10bfa63): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.4.24 (124e06aa)
# OS: Linux 3.10.0-1160.el7.x86_64 x86_64 CentOS Linux release 7.9.2009 (Core) xfs
# Hostname: mail.domain.com
auth_debug = yes
auth_mechanisms = plain login
first_valid_uid = 1000
mail_location = maildir:/home/vmail/%d/%n
mail_privileged_group = vmail
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date index ihave duplicate mime foreverypart extracttext
mbox_write_locks = fcntl
namespace inbox {
inbox = yes
location =
mailbox Drafts {
special_use = \Drafts
}
mailbox Junk {
special_use = \Junk
}
mailbox Sent {
special_use = \Sent
}
mailbox "Sent Messages" {
special_use = \Sent
}
mailbox Trash {
special_use = \Trash
}
prefix = INBOX.
separator = .
type = private
}
passdb {
args = /etc/dovecot/dovecot-sql.conf.ext
driver = sql
}
plugin {
sieve = file:~/sieve;active=~/.dovecot.sieve
}
service auth-worker {
user = root
}
service auth {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0666
user = postfix
}
unix_listener auth-master {
mode = 0600
user = vmail
}
user = root
}
service imap-login {
inet_listener imap {
port = 143
}
inet_listener imaps {
port = 993
ssl = yes
}
}
service lmtp {
unix_listener /var/spool/postfix/private/dovecot-lmtp {
group = postfix
mode = 0600
user = postfix
}
unix_listener lmtp {
mode = 0666
}
}
service pop3-login {
inet_listener pop3 {
port = 110
}
inet_listener pop3s {
port = 995
ssl = yes
}
}
ssl = required
ssl_cert = </etc/letsencrypt/live/mail.domain.com/fullchain.pem
ssl_key = # hidden, use -P to show it
userdb {
args = /etc/dovecot/dovecot-sql.conf.ext
driver = sql
}
userdb {
args = uid=5000 gid=5000 home=/home/vmail/%d/%n allow_all_users=yes
driver = static
}
protocol lda {
auth_socket_path = /var/run/dovecot/auth-master
log_path = /home/vmail/dovecot-deliver.log
postmaster_address = postmaster@domain.com
}
protocol pop3 {
pop3_uidl_format = %08Xu%08Xv
}

Please help me

You may try the following in postfix main.cf file:
See this post for details

Thanks this solved temprorary my problem.

This helped but now have new issue

Mar 22 11:43:10 mail postfix/pipe[31179]: 3C845FNBC5: to=<user@gmail.com>, relay=dovecot, delay=0.38, delays=0.3/0.02/0/0.06, dsn=2.0.0, status=sent (delivered via dovecot service)

from user@domain.com to user@gmail.com it can't be deliveried but there is no issue.

now i can only receive but i can't send the mail.

[root@mail postfix]# postconf -n
postconf: warning: /etc/postfix/main.cf: undefined parameter: virtual_mailbox_limit_maps
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
append_dot_mydomain = no
biff = no
broken_sasl_auth_clients = yes
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
debug_peer_level = 2
debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin ddd $daemon_directory/$process_name $process_id & sleep 5
html_directory = no
inet_interfaces = all
inet_protocols = all
mail_owner = postfix
mailbox_command = /usr/lib/dovecot/deliver
mailbox_transport = lmtp:unix:/var/spool/postfix/private/dovecot-lmtp
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
message_size_limit = 30720000
mua_client_restrictions = permit_sasl_authenticated, reject
mua_helo_restrictions = permit_mynetworks, reject_non_fqdn_hostname, reject_invalid_hostname, permit
mua_sender_restrictions = permit_sasl_authenticated, reject
mydestination = mail.domain.com
myhostname = mail.domain.com
myorigin = domain.com
newaliases_path = /usr/bin/newaliases.postfix
proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks $virtual_mailbox_limit_maps
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-2.10.1/README_FILES
sample_directory = /usr/share/doc/postfix-2.10.1/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, permit
smtpd_restriction_classes = mua_sender_restrictions, mua_client_restrictions, mua_helo_restrictions
smtpd_sasl_auth_enable = yes
smtpd_sasl_authenticated_header = yes
smtpd_sasl_path = private/auth
smtpd_sasl_type = dovecot
smtpd_tls_cert_file = /etc/letsencrypt/live/mail.domain.com/fullchain.pem
smtpd_tls_key_file = /etc/letsencrypt/live/mail.domain.com/privkey.pem
smtpd_use_tls = yes
unknown_local_recipient_reject_code = 550
virtual_alias_domains =
virtual_alias_maps = mysql:/etc/postfix/mysql_alias.cf
virtual_gid_maps = static:5000
virtual_mailbox_base = /home/vmail
virtual_mailbox_domains = mysql:/etc/postfix/mysql_domains.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql_users.cf
virtual_transport = dovecot
virtual_uid_maps = static:5000

postconf -n updated
and doveconf -n

# 2.2.36 (1f10bfa63): /etc/dovecot/dovecot.conf
# OS: Linux 3.10.0-1160.108.1.el7.x86_64 x86_64 CentOS Linux release 7.9.2009 (Core) xfs
# Hostname: mail.domain.com
auth_mechanisms = plain login
first_valid_uid = 1000
listen = *
mail_location = maildir:/home/vmail/%d/%n
mbox_write_locks = fcntl
namespace inbox {
hidden = no
inbox = yes
location =
mailbox Drafts {
special_use = \Drafts
}
mailbox Junk {
special_use = \Junk
}
mailbox Sent {
special_use = \Sent
}
mailbox "Sent Messages" {
special_use = \Sent
}
mailbox Trash {
special_use = \Trash
}
prefix = INBOX.
separator = .
type = private
}
passdb {
args = /etc/dovecot/dovecot-sql.conf.ext
driver = sql
}
protocols = imap lmtp
service auth-worker {
user = root
}
service auth {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0666
user = postfix
}
unix_listener auth-master {
mode = 0600
user = vmail
}
user = root
}
service imap-login {
inet_listener imap {
port = 143
}
inet_listener imaps {
port = 993
ssl = yes
}
}
service lmtp {
unix_listener /var/spool/postfix/private/dovecot-lmtp {
group = postfix
mode = 0600
user = postfix
}
unix_listener lmtp {
mode = 0666
}
}
service pop3-login {
inet_listener pop3 {
port = 110
}
inet_listener pop3s {
port = 995
ssl = yes
}
}
ssl = required
ssl_cert = </etc/letsencrypt/live/mail.domain.com/fullchain.pem
ssl_key = # hidden, use -P to show it
userdb {
args = /etc/dovecot/dovecot-sql.conf.ext
driver = sql
}
userdb {
args = uid=5000 gid=5000 home=/home/vmail/%d/%n allow_all_users=yes
driver = static
}
protocol lda {
auth_socket_path = /var/run/dovecot/auth-master
log_path = /home/vmail/dovecot-deliver.log
postmaster_address = postmaster@domain.com
}
protocol pop3 {
pop3_uidl_format = %08Xu%08Xv
}

Mar 22 11:49:14 mail postfix/smtps/smtpd[31173]: warning: hostname 11-111-111-11.domain.com does not resolve to address 11.111.111.11: Name or service not known
Mar 22 11:49:14 mail postfix/smtps/smtpd[31173]: connect from unknown[11.111.111.11]
Mar 22 11:49:14 mail postfix/smtps/smtpd[31173]: DA6EAFCBC5: client=unknown[11.111.111.11], sasl_method=PLAIN, sasl_username=user@domain.com
Mar 22 11:49:15 mail postfix/cleanup[31562]: DA6EAFCBC5: message-id=<665f52db-938d-494a-9a5c@email.android.com>
Mar 22 11:49:15 mail postfix/qmgr[31092]: DA6EAFCBC5: from=<user@domain.com>, size=726, nrcpt=1 (queue active)
Mar 22 11:49:15 mail postfix/pipe[31564]: DA6EAFCBC5: to=<user@gmail.com>, relay=dovecot, delay=0.31, delays=0.23/0.02/0/0.07, dsn=2.0.0, status=sent (delivered via dovecot service)
Mar 22 11:49:15 mail postfix/qmgr[31092]: DA6EAFCBC5: removed

I don't know why postfix tries to deliver message for gmail.com locally through dovecot? Maybe it thinks that gmail.com is a local (virtual?) domain!
Use postfix tools to look at the virtual domains/maps database