Postfix Config

main.cf

## These are all default Postfix settings that we won't change
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
append_dot_mydomain = no
biff = no
broken_sasl_auth_clients = yes
inet_interfaces = all
mailbox_command = /usr/lib/dovecot/deliver -c
    /etc/dovecot/conf.d/01-mail-stack-delivery.conf -m "${EXTENSION}"
mailbox_size_limit = 0
myorigin = /etc/mailname
readme_directory = no
recipient_delimiter = +
relayhost =
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_sasl_auth_enable = yes
smtpd_sasl_authenticated_header = yes
smtpd_sasl_path = private/dovecot-auth
smtpd_sasl_security_options = noanonymous
smtpd_sasl_local_domain = $myhostname
smtpd_sasl_type = dovecot
smtpd_tls_auth_only = yes
smtpd_tls_received_header = yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
tls_random_source = dev:/dev/urandom
 
## Settings below this line are things we're modifying or adding
 
## Your mail server identity options
myhostname = mail.yourdomain.com
mydestination = localhost, mail.yourdomain.com,
    localhost.yourdomain.com
mynetworks = 127.0.0.0/8 192.168.0.0/24 [::ffff:127.0.0.0]/104 [::1]/128
 
## Customized smtpd paramters
smtpd_banner = $myhostname ESMTP
smtpd_helo_required = yes
smtpd_helo_restrictions = permit_mynetworks,
    reject_non_fqdn_helo_hostname, reject_invalid_helo_hostname,
    reject_unknown_helo_hostname, permit
smtpd_recipient_restrictions = reject_unknown_client_hostname,
    reject_unknown_sender_domain, reject_unknown_recipient_domain,
    reject_unauth_pipelining, permit_mynetworks,
    permit_sasl_authenticated, reject_unauth_destination, 
    reject_invalid_hostname, reject_non_fqdn_sender
smtpd_sender_restrictions = reject_unknown_sender_domain,
    reject_sender_login_mismatch
smtpd_sender_login_maps = $virtual_mailbox_maps
 
## Dealing with rejection: use permanent 550 errors to stop retries
unknown_address_reject_code = 550
unknown_hostname_reject_code = 550
unknown_client_reject_code = 550
 
## customized TLS parameters
smtpd_tls_ask_ccert = yes
smtpd_tls_cert_file = /etc/ssl/private/ssl-chain-mail-yourdomain.pem
smtpd_tls_key_file = /etc/ssl/private/ssl-key-decrypted-mail-yourdomain.key
smtpd_tls_CAfile = /etc/ssl/certs/ca-certificates.crt 
smtpd_tls_ciphers = high
smtpd_tls_loglevel = 1
smtpd_tls_security_level = may
smtpd_tls_session_cache_timeout = 3600s
 
## Customized Dovecot and virtual user-specific settings
canonical_maps = hash:/etc/postfix/canonical
home_mailbox = Maildir/
message_size_limit = 104857600
virtual_alias_maps = hash:/etc/postfix/virtual
virtual_mailbox_domains = hash:/etc/postfix/virtual-mailbox-domains
virtual_mailbox_maps = hash:/etc/postfix/virtual-mailbox-users
virtual_transport = dovecot
 
## This setting will generate an error if you restart Postfix before
## adding the appropriate service definition in master.cf, so make
## sure to get that taken care of!
dovecot_destination_recipient_limit = 1
 
## Customized milter settings
#milter_default_action = accept
#milter_connect_macros = j {daemon_name} v {if_name} _
#non_smtpd_milters = $smtpd_milters
#smtpd_milters = unix:/spamass/spamass.sock unix:/clamav/clamav-milter.ctl
#   unix:/opendkim/opendkim.sock
 
## Other customized mail server settings
default_destination_concurrency_limit = 5
disable_vrfy_command = yes
relay_destination_concurrency_limit = 1
smtp_tls_note_starttls_offer = yes
smtp_tls_security_level = may