I'm trying to build send only mail server using postfix. I folowed this [documentation](https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-postfix-as-a-send-only-smtp-server-on-ubuntu-16-04) from digital ocean

When I try to send email, it gives below error. (I copied from /var/log/mail.log)

lets say my domain name is `domainaddress.com`

```
Feb  9 07:52:54 domainaddress postfix/qmgr[22091]: B22861BA03A: from=<hsntngr@domainaddress>, size=403, nrcpt=1 (queue active)
Feb  9 07:52:54 domainaddress postfix/smtp[26332]: connect to domainaddress[127.0.1.1]:25: Connection refused
Feb  9 07:52:54 domainaddress postfix/smtp[26333]: connect to domainaddress[127.0.1.1]:25: Connection refused
Feb  9 07:52:54 domainaddress postfix/smtp[26332]: 6A8D81BA0FA: to=<hsntngr@domainaddress>, relay=none, delay=29909, delays=29909/0.01/0/0, dsn=4.4.1, status=deferred (conn$
Feb  9 07:52:54 domainaddress postfix/smtp[26332]: connect to domainaddress.com[128.199.50.100]:25: Connection refused
Feb  9 07:52:54 domainaddress postfix/smtp[26333]: 6CDC81BA03F: to=<hsntngr@domainaddress>, relay=none, delay=126295, delays=126295/0.01/0/0, dsn=4.4.1, status=deferred (co$
Feb  9 07:52:54 domainaddress postfix/smtp[26332]: 6BDFF1BA0F8: to=<hsntngr@domainaddress.com>, relay=none, delay=29997, delays=29997/0.02/0/0, dsn=4.4.1, status=deferred ($
Feb  9 07:52:54 domainaddress postfix/smtp[26333]: connect to domainaddress[127.0.1.1]:25: Connection refused
Feb  9 07:52:54 domainaddress postfix/smtp[26333]: B22861BA03A: to=<your_email_address@domainaddress>, relay=none, delay=126304, delays=126304/0.02/0.01/0, dsn=4.4.1, status..

```

Even if I setup my host name in config file, host name seems wrong..

Also my config file (/etc/postfix/main.cf)

```
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = mail.domainaddress.com
mydomain = domainaddress.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = $myhostname
mydestination = $myhostname, localhost, $mydomain , www.$mydomain    
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = loopback-only
inet_protocols = ipv4

```

I know I'm doing something wrong at somewhere but I couldn't figure out what it is and where, for two days.