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LPCSubstations's profile

5 Messages

Tuesday, May 14th, 2024 2:57 PM

Black listed email

I work for a public utility, we use an email server that sends out MMS messages to our workers showing that there are power outages or issues with the system.  They are no longer receiving those messages.  I think my address has been black listed for spam although it is not.  I receive this message back after the SMS has been sent.

Reporting-MTA: dns;NETMAST.lpcscada.com
Received-From-MTA: dns;lpcscada.com
Arrival-Date: Tue, 14 May 2024 04:57:51 -0600

Final-Recipient: rfc822;[email scrubbed]
Action: failed
Status: 5.2.0
Diagnostic-Code: smtp;552 5.2.0 _fromemail> sender rejected AUP#SNDR

I am pretty sure my sending email has been blacklisted.  How do I get this removed, so that my workers can be contacted about outages again?

Accepted Solution

ACE - Expert

 • 

35.9K Messages

1 month ago

Do you have DKIM, SPF and DMARC set up?  

Do you have PTR records for your mail server IP to your domain

Is your FROM address domain always consistently matching the domain pointed to by the PTR?

Accepted Solution

ACE - Expert

 • 

35.9K Messages

1 month ago

Many of the major mail handling companies (Yahoo, Google, etc.) have been tightening up the requirements under which they will accept e-mail.  I've listed the ones I can think of off the top of my head, but there are probably more.  https://mxtoolbox.com is a good resource for this.  Yahoo also has pages about requirements for accepting e-mail.

5 Messages

1 month ago

I unfortunately do not have any of those as it is an old system. I am sure you will tell me I need to set those things up before this will work again?  Thank you for your quick response and help BTW.

5 Messages

1 month ago

I take it ATT has the same requirements as it is the MMS from my email server that is getting blocked by AT&T?

ACE - Expert

 • 

35.9K Messages

1 month ago

I would not say that they're exactly the same, but they will share the same minimum requirements.  Yahoo handles much of AT&T's mail handling, so their requirements apply as well as AT&T's.

5 Messages

1 month ago

Thank you for your help Jeffer.

5 Messages

1 month ago

The above solution was correct I added an SPF and am now able to receive the messages.  

Thank you Jeffer

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