How to fix 'Relay Access Denied'

Question

I'm trying to setup postfix as MTA on a AWS EC2 instance. I want to use this as mailserver for my domains and want to use it along with Outlook/Thunderbird.

I've never setup postfix before, therefore I used this great guide here:

http://flurdy.com/docs/postfix/

Now I can connect to the server via STARTTLS to mail.mydomain.com and send emails to my own email account [email protected] via Thunderbird.

However when I try to send an email to an external domain [email protected] I get an error Relay access denied.

The logs show:

May 31 14:55:58 ip-172-31-23-97 postfix/smtpd[13500]: NOQUEUE: reject: RCPT from myhostname[97.192.4.67]: 554 5.7.1 <[email protected]>: Relay access denied; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<[192.168.178.64]>

My postfix config:

http://pastebin.com/0jytH4Yi

I know there are many pages out there that address this issue.

Mainly the issue can be fixed by adjusting mynetworks, smtpd_recipient_restrictions or smtpd_relay_restrictions but none of the changes fixed my issue.

What can I do to resolve this?

Solution

I think the problem is here

#mynetworks = 168.100.189.0/28, 127.0.0.0/8

Try to add and network 192.168.178.0/24 and del #

mynetworks = 127.0.0.0/8, 192.168.178.0/24

Comments

[maddo7]

Are you sure? I don't have sasl installed on the machine and smtp_sasl_auth_enable is only used for the smtp connection for amazon's ses smtp server.

[maddo7]

Unfortunately after uncommenting the line and adding your suggestion I'm still getting the error

[stambata]

Is this your LAN 192.168.178.0/24?

[maddo7]

Edit: Yes, that's the LAN IP of my windows PC from where I try to connect. How can the LAN IP be related to this?

[maddo7]

When I insert the internet IP address of my connection to that value, it sends the email without problems: mynetworks = 168.100.189.0/28, 127.0.0.0/8, 192.168.178.0/24, 172.31.23.0/24, xxx.193.4.67 but I don't want to manually insert the IP addresses of all clients I want to use to connect.

[stambata]

This is another issue :). and your solution is SASL postfix.org/SASL_README.html