I have a mail server setup on Ubuntu 10.04 using postfix and dovecot. I can receive emails on email client like thunderbird, but I can send emails using the same client. Below is the postfix config file main.cf
# See /usr/share/postfix/main.cf.dist for a commented, more complete version
# Debian specific: Specifying a file name will cause the first
# line of that file to be used as the name. The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
# appending .domain is the MUA's job.
append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = no
# TLS parameters
smtpd_tls_cert_file = /etc/ssl/certs/smtpd.crt
smtpd_tls_key_file = /etc/ssl/private/smtpd.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
myhostname = mail.xxx.xxxx
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = xxx.xxxx.xxxx
smtp_bind_address = xxxxxxxxxx
mydestination = mail.xxxxxx, localhost.xxxxxx, localhost, xxxxx
relayhost =
mynetworks = 127.0.0.0/8,
mailbox_size_limit = 0
recipient_delimiter = +
#inet_interfaces = all
inet_protocols = all
#home_mailbox = mail/
#home_mailbox = /var/mail/%u
mailbox_command =
smtpd_sasl_local_domain =
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
#smtpd_recipient_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination
smtp_tls_security_level = may
smtpd_tls_security_level = may
smtpd_tls_auth_only = no
smtp_tls_note_starttls_offer = yes
smtpd_tls_CAfile = /etc/ssl/certs/cacert.pem
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom
mail_spool_directory = /var/spool/mail
content_filter =
#######################################################################################################################################
smtpd_recipient_restrictions = reject_invalid_hostname,
reject_non_fqdn_sender,
reject_non_fqdn_recipient,
reject_unknown_sender_domain,
reject_unknown_recipient_domain,
reject_unauth_pipelining,
permit_sasl_authenticated,
permit_mynetworks,
reject_unauth_destination,
reject_rbl_client dnsbl.njabl.org,
reject_rbl_client cbl.abuseat.org,
reject_rbl_client sbl.spamhaus.org,
# check_recipient_mx_access hash:/etc/postfix/recipient_mx_access
smtpd_client_restrictions = permit_mynetworks,
permit_sasl_authenticated,
permit_inet_interfaces,
reject_rbl_client zen.spamhaus.org
reject_unknown_reverse_client_hostname
smtpd_sender_restrictions = reject_non_fqdn_sender,reject_unknown_sender_domain
##########################################################################################################################################
#header_checks = regexp:/etc/postfix/header_checks