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msidnamFlag for United States of America

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Our emails are going to SPAM for several recipients but we are not on any RBL's

I know the answer will be "have them add you to the whitelist", however this started to happen all at once today. For some reason about 6 or so clients told us that all our emails went right to their spam folder. We use a third party to send the emails (mimecast) and their IP's are not on any RBL's and they say its on the recipients side

One client is rejecting our emails but the error is vague.  Their IT guy is telling me that its not the IP being blocked but the content based on the "fingerprint" of the email. Yet he says the way to check the "fingerprint" isn't available to the public.

While researching the fingerprint, the only thing i came up with is something called Vipuls Razor that became a way to detect spam based on the email and not the domain, sender or IP. This is one snippet he sent me:

That fingerprint is for the IP address X.X.X.X, which sent messages that were reported spam by end users.

Looking at the feedback I see:
- 100% of reports seen were to block
- 0% of blocks were from spam traps
- First report : 2016-01-29 16:19:09
- Last report : 2016-02-29 19:26:19

The problem is, the IP they mention is not the one sending emails. It's the IP of my server, but I use mimecast as a smart host so my server IP never makes a connection and we have it locked down internally.

Another problem i have is that if i find out how to fix it i dont have a good way to test.

Has anyone come across this before? I feel like i'm in the middle of an email mafia.
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Based on the report, what you posted and the hosted email system you use, all you can do is be whitelisted by your recipients.

If the hosted email IP is a problem, whitelisting may not help either.

Have you contacted your email supplier with the report?
Avatar of Mal Osborne
A couple of things to check:

1. A PTR record for your mail server. If  you do not have one, expect a LOT of email to be rejected outright.

2. An SPF record (correctly set). Without this, expect a few emails to be misidentified as spam.

If you can post your domain name and sending IP,  one of us can check these things out for you
".............about 6 or so clients told us that all our emails went right to their spam folder................"

Are you referring to the Outlook Junk E-Mail ?

Avatar of msidnam


As far as what I'm hearing from the clients, its going to their spam box from whatever service they are using. We use Mimecast and we have an area called On Hold Messages. I would imagine they have something similar. Its not going to the outlook SPAM box.

I've noticed that anyone using is blocking us. If they are using rackspace, it goes to SPAM. I think rackspace uses cloudmark and we are trying to see if we can get off their spam list.

We do have an SPF record. But I dont know about a PTR record since Mimecast's IP's are the ones sending the mail.

One thing to keep in mind is everything was working for years with no issues until yesterday. And i am not sure how to find out what happened or who started tagging us as spam. It's especially hard since no IP's are on RBL's and mimecast support said its not them and its on the recipients side.

Here is a bounce back from one of the domains:

"This is a delivery failure notification message indicating that an email you addressed to email address :

could not be delivered. The problem appears to be :
-- Recipient email server rejected the message

Additional information follows :
-- 5.7.1 u23KZInx003766 This message does not comply with required standards.

This condition occurred after 1 attempt(s) to deliver over a period of 0 hour(s).

If you sent the email to multiple recipients, you will receive one of these messages for each one which failed delivery,  otherwise they have been sent."

how can i tell who or what has me on a a spam list since none of the IP's are on RBL's?
You need to contact the recipient and see if they can help explain and at the same time whitelist you.
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