I tried but the delivery rate is very slow I am using Debian and iredmail 6.1 my postfix send only 10k emails per hour is there any parameters which i change and my server start sending atleast 70k mails per hour.

alias_database = hash:/etc/postfix/aliases
alias_maps = hash:/etc/postfix/aliases
allow_min_user = no
append_dot_mydomain = no
biff = no
bounce_queue_lifetime = 1d
broken_sasl_auth_clients = yes
config_directory = /etc/postfix
content_filter = smtp-amavis:[127.0.0.1]:10024
delay_warning_time = 0h
disable_vrfy_command = yes
enable_original_recipient = no
home_mailbox = Maildir/
inet_interfaces = all
inet_protocols = ipv4
mail_name = zmail
mail_version = 1
mailbox_command = /usr/lib/dovecot/deliver
mailbox_size_limit = 15728640
maximal_backoff_time = 4000s
maximal_queue_lifetime = 1d
minimal_backoff_time = 300s
mydestination = $myhostname, localhost, localhost.localdomain, localhost.$myhostname
mydomain = xyz-inc.com
myhostname = mail.xyz-inc.com
mynetworks = 127.0.0.0/8,
mynetworks_style = subnet
myorigin = mail.xyz-inc.com
proxy_read_maps = $canonical_maps $lmtp_generic_maps $local_recipient_maps $mydestination $mynetworks $recipient_bcc_maps $r$
queue_run_delay = 300s
readme_directory = no
recipient_bcc_maps = proxy:mysql:/etc/postfix/mysql_recipient_bcc_maps_domain.cf, proxy:mysql:/etc/postfix/mysql_recipient_b$
recipient_delimiter = +
relay_domains = $mydestination, proxy:mysql:/etc/postfix/mysql_relay_domains.cf
relay_recipient_maps = proxy:mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
relayhost =
sender_bcc_maps = proxy:mysql:/etc/postfix/mysql_sender_bcc_maps_domain.cf, proxy:mysql:/etc/postfix/mysql_sender_bcc_maps_u$
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
smtpd_data_restrictions = reject_unauth_pipelining
smtpd_enforce_tls = no
smtpd_helo_required = yes
smtpd_helo_restrictions = permit_mynetworks,permit_sasl_authenticated, check_helo_access pcre:/etc/postfix/helo_access.pcre
smtpd_recipient_restrictions = reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_non_fqdn_sender, reject$
smtpd_reject_unlisted_recipient = yes
smtpd_reject_unlisted_sender = yes
smtpd_sasl_auth_enable = yes
smtpd_sasl_authenticated_header = no
smtpd_sasl_local_domain =
smtpd_sasl_path = dovecot-auth
smtpd_sasl_security_options = noanonymous
smtpd_sasl_type = dovecot
smtpd_sender_login_maps = proxy:mysql:/etc/postfix/mysql_sender_login_maps.cf
smtpd_sender_restrictions = permit_mynetworks, reject_sender_login_mismatch, permit_sasl_authenticated
smtpd_tls_cert_file = /etc/ssl/certs/iRedMail_CA.pem
smtpd_tls_key_file = /etc/ssl/private/iRedMail.key
smtpd_tls_loglevel = 0
smtpd_tls_security_level = may
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtpd_use_tls = yes
tls_random_source = dev:/dev/urandom
transport_maps = proxy:mysql:/etc/postfix/mysql_transport_maps_user.cf, proxy:mysql:/etc/postfix/mysql_transport_maps_domain$
virtual_alias_maps = proxy:mysql:/etc/postfix/mysql_virtual_alias_maps.cf, proxy:mysql:/etc/postfix/mysql_domain_alias_maps.$
virtual_gid_maps = static:1001
virtual_mailbox_base = /var/vmail
virtual_mailbox_domains = proxy:mysql:/etc/postfix/mysql_virtual_mailbox_domains.cf
virtual_mailbox_maps = proxy:mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
virtual_minimum_uid = 1001
virtual_transport = dovecot
virtual_uid_maps = static:1001

Second, bypass anti-spam, anti-virus for outgoing mails in Amavisd-new.

- Add below settings in /etc/amavisd.conf policy_bank "MYNETS", "MYUSERS", "ORIGINATING":

    bypass_spam_checks_maps => [1],
    bypass_banned_checks_maps => [1],
    bypass_header_checks_maps => [1],

If you don't need anti-spam/anti-virus at all, remove/comment "content-filter =" in postfix main.cf, and then disable amavisd, clamd, freshclam services.

These 3 tips should speed up rate of outgoing mails, please share your feedback with us.

Policyd will listen on port 10031 and 10032 (optional), remove related settings in postfix main.cf should be enough.

/etc/amavisd.conf this file is not availbale on my server I am on debian.

Recipient address rejected: Policy Rejection- Quota Exceeded.; from=<> to=<bounce@zarca-inc.com> proto=ESMTP helo=<smtp1.barwa.com.qa>

why this error is coming I have not enable policyd on my server