ispconfig 3.2.12p1 postfix mail relay without authentication not working on some relayhosts

Hello,
i have a problem on some relay servers. They do not accept the mails from domains.
at the moment we have set under Specific domains a relay to a outbound gateway:
Email -> Domain ->Choose Domain
Relayhost -> Relay Server DNS or IP
Relayhost User -> Empty
Relayhost Password -> Empty
One Relay Server is working but another gateway does not
warning: SASL authentication failure: All-whitespace username
SASL authentication failed; cannot authenticate to server: generic failure
We have entered the sql query in the mysql server:
SELECT relay_host as relayhost FROM mail_domain WHERE domain = 'domain' AND active = 'y' AND concat(relay_host,relay_user,relay_pass) != '' AND server_id = 1
If there is no PW and User set we get only the relay_host back.

nano /etc/postfix/mysql-virtual_sender-relayhost.cf
user = isp
password = pw
dbname = dbname
hosts = 127.0.0.1
query = SELECT relay_host as relayhost
FROM mail_domain WHERE domain = '%d' AND active = 'y' AND concat(relay_host,relay_user,relay_pass) != '' AND server_id = 1

This works.. but on one server we get the above error.
Could anyone help?
Regards
Dominik

 

Hi Till,
thanks for the quick help this solved the issue, i think you should check this to implement it to your source.
I use this to implement Cloud Security Gateway from other vendors for Customers who wants more protection than rspamd does.
Regards

Dominik