Error sending email #< #5.4.6 smtp; 551 5.4.6 [internal] Private/Loopback Address> #SMTP#

[Migration User]

I need help! O got the error messagem when sending email to a specific address:

#< #5.4.6 smtp; 551 5.4.6 [internal] Private/Loopback Address> #SMTP#

 

[TomVie]

Hi,

Sounds like your mails loops till max hop count is reached.

Are we talking about in- or outbound mails, from or to internet?

Thomas

[Migration User]

We are talking about outbound, to internet.

But I get the error at the same time I send it. Is the max hop count reached on this situation?

Thanks,

Alexandre

[TomVie]

The route for this Mail ends in a loop to yourself and this leads to the ndr. Only one Destination Domain or all outbound Mails? In case 1, check Protokoll Domains and or mx of dest In case 2, ip settings of your Scanner Thomas

[Migration User]

I got it!

The problem was with my firewall, which took a false attack when the DNS server consulted the specific domain, and returning 127.0.0.1.
So...the loopback.