server5.boonex.com, what you want on my smtp server?

Hello Boonex,

seriously pls can you tell me why your server5.boonex.com (173.192.33.210) is trying to login to my smtp server? it's getting more and more. Is your server hacked or what? That smells like a relay attack.

postfix/smtpd[3515]: connect from unknown[173.192.33.210]
postfix/smtpd[3512]: warning: 173.192.33.210: address not listed for hostname server5.boonex.com
postfix/smtpd[3510]: NOQUEUE: reject: RCPT from unknown[173.192.33.210]: 450 4.7.1 Client host rejected: cannot find your hostname, [173.192.33.210]; from=<www-data@server5.boonex.com> to=<XXXXXXX@XXXXXXXXXX.XXX> proto=ESMTP helo=<server5.boonex.com>

Do you want sent me an email to my registered email here or what is this?

Thx

Upon further reading the postfix documentation i found out that your server is misconfigured, my mail server rejects your machine because it thinks you are not a real client. It fails to pass reject_unknown_client_hostname

Can be closed, i think you only try to send me notifications about new mails or subscription updates here. YOu are really the first mail sender cannot pass my filter. ;) Never seen this before

did you gave a mail that is hosted on your server when you signed up at boonex?

Yes, i am sure now their mail server wants to send me subscription notifications to my smtp. I just wondered it got rejected and thought this server might be hacked, but its not. After checking the postfix docs, because i have never seen this error before, i realized its my policies here to reject any mail from misconfigured email servers. (reject_unknown_client_hostname).

i read this setting can be a problem because this can reject even legit servers trying to send emails. anyway, the mail server of boonex has a configuration problem. but i read on internet many have this, so better turn this off on my side.