Postfix - status=bounced (unknown user "myuser")

I am configuring Postfix and when validating by telnet and SMTP I got the status bounced error, unknown user:

Error log:

> postfix/local[18718]: 4590D7DC0A51: to=<[email protected]>, relay=local, delay=9.8, delays=9.8/0.01/0/0.04, dsn=5.1.1, status=bounced (unknown user: "myuser")

The "myuser" already exists, but with full domain name: [email protected].

User Validation:

 postmap -q myuser@mydomain.com mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf

Output is: "1" - so I guess it is OK.

My postfix Configuration:

root# postconf -n:
append_at_myorigin = yes
biff = no
config_directory = /etc/postfix
default_destination_concurrency_limit = 1
delay_warning_time = 8h
disable_vrfy_command = yes
dovecot_destination_concurrency_limit = 1
dovecot_destination_recipient_limit = 1
enable_original_recipient = yes
local_destination_concurrency_limit = 1
maximal_queue_lifetime = 6d
mydestination = mydomain.com
smtpd_client_restrictions = permit_mynetworks, permit_sasl_authenticated
smtpd_delay_reject = no
smtpd_hard_error_limit = 10
smtpd_helo_required = yes
smtpd_helo_restrictions = permit_mynetworks, reject_invalid_hostname
smtpd_recipient_restrictions = permit_mynetworks, reject_unknown_sender_domain,             reject_unknown_recipient_domain, reject_unlisted_recipient, reject_unauth_destination, reject_unauth_pipelining
smtpd_sender_restrictions = permit_mynetworks, reject_unknown_sender_domain
smtpd_soft_error_limit = 5
strict_rfc821_envelopes = yes
virtual_alias_maps = mysql:/etc/postfix/mysql-virtual-alias-maps.cf,mysql:/etc/postfix/mysql-email2email.cf
virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf
virtual_transport = dovecot

Thank you for any help.

you have added mydestination = mydomain.com and so the valid users for mydomain.com will be searched in local_recipient_maps. It is very clear from the logline that local delivery agent is selected to deliver the mail, as local domain class matched. See postfix address classes for more help

Modify your main.cf like below

#/etc/postfix/main.cf
mydestination = 
# set to localhost localhost.$mydomain or remove mydomain.com for now
# Ensure that postmap -q mydomain.com mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf is returning mydomain.com and 
# postmap -q [email protected] mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf succeeds

Use following settings in /var/postfix/main.cf

myorigin = localhost
myhostname = <your_host_name>
mydestination = localhost.$mydomain, localhost, localhost.localdomain

followed by:

sudo postmap /etc/postfix/virtual
sudo service postfix restart

Open /etc/postfix/main.cf, look for the mydestination field and change it's value to the below

mydestination = localhost, localhost.localdomain

Don't forget to run sudo postfix reload afterwards

For someone else, when I set mydestination=mydomain.com. Postfix show warning do not list domain mydomain.com in BOTH mydestination and virtual_mailbox_domains. So I set it relayhost = mydomain.com

My postfix version: 3.1.0 (postconf -d | grep mail_version)