SMTP Error 550 5.1.0 SMTP Authentication required from your IP

[mzero]

Hello everyone,

There are multiple threads about the error message I got, but none of the solutions seem to work.

The error message from Mail Delivery System:

[email protected]
   SMTP error from remote mail server after MAIL FROM:<[email protected]> SIZE=1687:
   host mail.upcmail.nl [ipv6_address]:
   550 5.1.0 Policy violation: SMTP Authentication required from your IP [my_ipv6_address]. Please provide Username and Password when sending Emails.

/var/log/exim/mainlog

2014-09-18 19:08:51 1XUfCL-0000J1-SC ** [email protected] F=<[email protected]> R=lookuphost T=remote_smtp: SMTP error from remote mail server after MAIL FROM:<[email protected]> SIZE=1687: host mail.upcmail.nl [ipv6_address]: 550 5.1.0 Policy violation: SMTP Authentication required from your IP [my_ipv6_address]. Please provide Username and Password when sending Emails.

I get these messages when sending mail from Outlook, Apple Mail and Roundcube. I only seem to have this problem when sending mails to @upcmail.nl addresses.

I used telnet to test if I could connect to SMTP on port 587. Everything works fine. I can even send a mail from telnet to the @upcmail.nl addresses with a 250 OK message, but even then I get the Mail Delivery System reply with the same error.

The server I use is a Cent OS VPS preinstalled with Directadmin. DNS settings are handled somewhere else.

Thank you all for taking the time to read this.

 

[myH2Oservers]

We have a customer with the same problem (today). Email send through ipv4 is being accepted but through ipv6 was rejected with the same message.

Faulty ipv6 configuration at UPC their side??

 

[mzero]

Is there any way to change back to ipv4 for the time being?

 

[mzero]

UPC, the provider of upcmail.nl told me that there could be a problem with my reverseDNS, or that they're not fully supporting ipv6 yet.... so they don't know what the problem is, and they're not planning on fixing it... great.

I fixed it for now by changing the following in my /etc/exim.conf

Changed this:

remote_smtp:
  driver = smtp

To

remote_smtp:
  driver = smtp
  interface = 1.2.3.4

Source: http://help.directadmin.com/item.php?id=152

 

[myH2Oservers]

How did you report it to them? I will report the same issue, maybe it gets a bit more priority.

 

[nobaloney]

Is there any way to change back to ipv4 for the time being?

To change what back to use IPv4?

Jeff

 

[mzero]

How did you report it to them? I will report the same issue, maybe it gets a bit more priority.

I've sent the error message to them, with some extra information that sending from ipv4 does work, and that I'm sure that I'm authenticated (by sending emails from my smpt server by using telnet). I also told them that sending email over ipv6 does work to any other domain I could test, just not @upcmail.nl.

This is my UPC ticket #140919-000064. If anyone has this problem, you could refer to it.

To change what back to use IPv4?

Jeff

Sending mail from ipv4. But I already found a solution (see my previous post).

 

[mzero]

UPC told me that there could be a problem with my reverseDNS, but they didn't know for sure.... well it turned out they where right.
After changing from IPv6 to IPv4 everything worked fine for some time, but all of a sudden it stopped working and gave me this error:

550 5.1.0 Dynamic/Generic hostnames are blocked. Please contact your Email Provider.

I changed both my IPv4 and IPv6 PTR records and it's working for now. It seems to be sending from IPv4, although I commented my exim.conf changes out, and restarted the server. weird!