Is my clients email server blacklisted by AOL?

[thecomputerguy]

Client contacted me because "After I left his house" (Which was to install an Ubiquiti AP to get his Ring doorbell to work), he emailed me and said ever since I left his house his email which is at a .com he owns and he uses via a POP connection cannot send email to his Wife which is at an AOL.com email and here is the bounce back he gets ...

The original message was received at Fri, 2 Feb 2018 18:40:57 -0500 from
[10.30.71.207]

*** ATTENTION ***

This email is being returned to you because the remote server would not or
could not accept the message. The registeredsite servers are just reporting
to you what happened and are not the source of the problem.

The address which was undeliverable is in the section labeled:
"----- The following addresses had permanent fatal errors -----".

The reason your mail is being returned to you is in the section labeled:
"----- Transcript of Session Follows -----".

This section describes the specific reason your e-mail could not be
delivered.

Please direct further questions regarding this message to your e-mail
administrator.

--Registeredsite Postmaster

----- The following addresses had permanent fatal errors -----
<xxx@aol.com>
(reason: 521 5.2.1 : (CON:B1)
https://postmaster.aol.com/error-codes#554conb1)

----- Transcript of session follows ----- ... while talking to
mailin-01.mx.aol.com.:
>>> DATA
<<< 521 5.2.1 : (CON:B1) https://postmaster.aol.com/error-codes#554conb1
554 5.5.0 Remote protocol error

Final-Recipient: RFC822; xxx@aol.com
Action: failed
Status: 5.0.0
Remote-MTA: DNS; mailin-01.mx.aol.com
Diagnostic-Code: SMTP; 521 5.2.1 : (CON:B1) https://postmaster.aol.com/error-codes#554conb1
Last-Attempt-Date: Fri, 2 Feb 2018 18:40:59 -0500

Thoughts?

 

[Sky-Knight]

The fact that the bounce happened means his local network is working properly. That's the end of your involvement. No one can support aol.com

However, AOL.com has their own error codes that show what's going on.

This is the relavant line, straight from the message return

521 5.2.1 : (CON:B1) https://postmaster.aol.com/error-codes

Going here: https://postmaster.aol.com/error-codes

Then opening up CON, we find this:

554 CON:B1

• The IP address has been blocked due to a spike in recent complaints, poor reputation or policy reasons. Please visit our Guidelines and best practices sections for more information on our Technical and policy requirements.

So yeah, they've been black listed by AOL.com, at least temporarily.

 

[Computer Bloke]

"554 CON:B1
The IP address has been blocked due to a spike in recent complaints, poor reputation or policy reasons. Please visit our Guidelines and best practices sections for more information on our Technical and policy requirements."

Looks pretty clear to me. Get him to try sending from his own account to a throwaway Gmail account, and from the Gmail account to his wife's AOL account. (Are people really still using AOL?) That'll help to pin it down, but the most likely source of the trouble is his SMTP server - I'd guess incorrect reverse DNS, missing SPF, or something like that. In any case, unless you're managing his mail servers it's not your problem.

 

[thecomputerguy]

"554 CON:B1
The IP address has been blocked due to a spike in recent complaints, poor reputation or policy reasons. Please visit our Guidelines and best practices sections for more information on our Technical and policy requirements."

Looks pretty clear to me. Get him to try sending from his own account to a throwaway Gmail account, and from the Gmail account to his wife's AOL account. (Are people really still using AOL?) That'll help to pin it down, but the most likely source of the trouble is his SMTP server - I'd guess incorrect reverse DNS, missing SPF, or something like that. In any case, unless you're managing his mail servers it's not your problem.

Wouldn't the management need to be taken place on the recipients server a la AOL? I'm not saying I'm going to pursue that option at all, not even one bit, but it sounds like AOL is rejecting his SMTP which is a Network Solutions SMTP server so the whitelist SPF record would be on the recipients end right?

 

[thecomputerguy]

Wouldn't the management need to be taken place on the recipients server a la AOL? I'm not saying I'm going to pursue that option at all, not even one bit, but it sounds like AOL is rejecting his SMTP which is a Network Solutions SMTP server so the whitelist SPF record would be on the recipients end right?

And yes ... I hate AOL people

 

[Computer Bloke]

...so the whitelist SPF record would be on the recipients end right?

Er, no. Take a look at this - it's one of the best explanations I've come across:

https://blog.returnpath.com/how-to-explain-spf-in-plain-english/

Are you responsible for the mail servers, or for your client's relationship with Network Solutions? If not, you're off the hook.

 

[Markverhyden]

Pure coincidence if the email is sent from some other IP. As implied above this is not so simple in reality and, yes, AOL s*ck$. I have several customers that do mass mailing, all legit paid subs or opt in's, and out of the blue AOL will start blocking. No rhyme or reason.

This problem has been discussed before in more general terms.

1. Need to check the domain at mxtools as well as various RBL's.
2. It's possible that they may have a shared SMTP server, which means shared IP, and some other domain is causing the problem.