Jul 18 08:24:41 company imapd: LOGIN, user=user_name@domain.com, ip=[::ffff:111.111.11.11], protocol=IMAP
Jul 18 08:24:42 company imapd: DISCONNECTED, user=user_name@domain.com, ip=[::ffff:111.111.11.11], headers=0, body=0, rcvd=83, sent=409, time=1
Jul 18 08:25:19 company postfix/smtpd[29282]: connect from company.university.edu[111.111.11.11]
Jul 18 08:25:19 company postfix/smtpd[29282]: NOQUEUE: reject: RCPT from company.university.edu[111.111.11.11]: 554 5.7.1 <email@gmail.com>: Relay access denied; from=<user_name@domain.com> to=<email@gmail.com> proto=ESMTP helo=<UserPC>
Jul 18 08:25:19 company postfix/smtpd[29282]: disconnect from company.university.edu[111.111.11.11]
Jul 18 08:25:22 company imapd: DISCONNECTED, user=user_name@domain.com, ip=[::ffff:111.111.11.11], headers=13, body=142579, rcvd=3289, sent=215892, time=79

#
# Postfix MTA Manager Main Configuration File;
#
# Please do NOT edit this file manually;
#

#
# Postfix directory settings; These are critical for normal Postfix MTA functionallity;
#

command_directory = /usr/sbin
daemon_directory = /usr/lib/postfix
program_directory = /usr/lib/postfix

#
# Some common configuration parameters;
#

inet_interfaces = all
mynetworks = 127.0.0.0/8
mynetworks_style = host

myhostname = mail.domain.com
mydomain = domain.com
myorigin = $mydomain

smtpd_banner = $myhostname ESMTP 2.4.7.1 (Debian/GNU)
setgid_group = postdrop

#
# Receiving messages parameters;
#

mydestination = localhost, company
append_dot_mydomain = no
append_at_myorigin = yes
transport_maps = mysql:/etc/postfix/transport.cf

#
# Delivering local messages parameters;
#

mail_spool_directory = /var/spool/mail
mailbox_size_limit = 0
mailbox_command = procmail -a "$EXTENSION"

biff = no

alias_database = hash:/etc/aliases

local_recipient_maps =

#
# Delivering virtual messages parameters;
#
virtual_mailbox_maps=mysql:/etc/postfix/mysql_virt.cf
virtual_uid_maps=mysql:/etc/postfix/uids.cf
virtual_gid_maps=mysql:/etc/postfix/gids.cf
virtual_mailbox_base=/usr/local/virtual
virtual_maps=mysql:/etc/postfix/virtual.cf
virtual_mailbox_domains=mysql:/etc/postfix/virtual_domains.cf


#
# SASL paramters;
#
smtp_use_tls = yes
smtpd_use_tls = yes
smtpd_tls_auth_only = yes
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s

smtp_tls_CAfile = /etc/postfix/ssl/smptd.pem
smtp_tls_cert_file = /etc/postfix/ssl/smptd.crt
smtp_tls_key_file = /etc/postfix/ssl/smptd.key

smtpd_tls_CAfile = /etc/postfix/ssl/smptd.pem
smtpd_tls_cert_file = /etc/postfix/ssl/smptd.crt
smtpd_tls_key_file = /etc/postfix/ssl/smptd.key

smtpd_sasl_auth_enable = yes

smtpd_sasl_security_options = noanonymous

smtpd_sasl_local_domain =

broken_sasl_auth_clients = yes

smtpd_sender_restrictions =
        permit_sasl_authenticated
        permit_mynetworks

smtpd_recipient_restrictions =
        permit_sasl_authenticated
        check_recipient_access hash:/etc/postfix/filtered_domains
        permit_mynetworks
        reject_unauth_destination

smtpd_recipient_restrictions =
    permit_sasl_authenticated
    check_recipient_access hash:/etc/postfix/filtered_domains
    permit_mynetworks
    reject_unauth_destination

permit_sasl_authenticated

check_recipient_access

permit_mynetworks

smtpd_use_tls = no

mynetworks = 192.168.1.0/24 127.0.0.0/8

mydestinations = $mydomain, $myhostname, localhost, localhost.localdomain

relay_domains = $mydomain

#/etc/postfix/main.cf
mydomain = server1.domain.com
myhostname = $mydomain
virtual_alias_maps = hash:/etc/postfix/virtual
alias_database = hash:/etc/postfix/virtual
myorigin = /etc/mailname
mydestination = localhost.localdomain localhost $mydomain
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all

sudo service networking restart

sudo service postfix reload