Blacklist.ie

Blacklist.ie is a free service to check if your IP address is blacklisted, a common cause of email delivery issues. Only a small number of blacklists affect your email delivery. With blacklist.ie, you can find out if you're on any of the blacklists most relevant to Ireland.

What is an IP address?

An IP address (Internet Protocol address) is a unique address that computers and other devices use in order to identify and communicate with each other on a computer network. An IP address simply identifies a specific computer on a network. More FAQs...

About IE Internet

IE Internet.com is a leading Irish technology company that provides managed email and application hosting services for business. Blacklist.ie is a service we have developed with the needs of our customers in mind.

Your good email message gets classified as spam

One of the most common issues is that your message arrives to spam/junk folder. Those folders are not monitored by many users, they are automatically purged (usually messages in those folders are removed after 7 or 30 days). Ultimately the recipient does not notice your message which can even lead to missed contract (customer thinks his/her questions are ignored, invoice undelivered, etc. Based on personal experience I will give a few hints which may help you to resolve this issue.

Start

You need to be able to get an email client where you can fully control all the client headers. My favourite goes to 'mutt'. Remove any headers you can and send plain text test message to the problematic recipient. If it's delivered than you need to look at differences first in headers and then in content between the spam classified message and the test one.

In case the recipient mail server is managed by smaller, responsible provider or maybe even customer's inhouse server you can just ask the recipient to contact the mail server administrator to tell you why the message gets flagged as spam and how to avoid it.

 

In case the recipient mail server belongs to some big free mail provider you can try to create your own mailbox with that provider and try to fully diagnose what could be the issue. I mean there is no problem with creating a test account with Gmail, Yahoo.com or Hotmail.com.

 

And always just to make sure it's not something obvious try to use this service:

https://www.mail-tester.com/

 

Yahoo spam classification

It appears to me Yahoo is very fragile to the following:

- user-agent header - always check what does your email sending software puts there. I had a case where emails were spam classified only because I had user-agent generated by the software that was sending the email. Once removed emails started flowing to Inbox.  

- from header without name - Yahoo marked as spam (instead of mydomain.com I had correct domain):

  From: This email address is being protected from spambots. You need JavaScript enabled to view it.

  to get it resolved I had to change the 'From' header to:

  From: "Ted Baker" <This email address is being protected from spambots. You need JavaScript enabled to view it. >

- from header with apostrophe in the name - ie. irish last name:

  From: "Tom O'Brien" <This email address is being protected from spambots. You need JavaScript enabled to view it. >

  to get it resolved I had to change the 'From' header to:

  From: "Tom OBrien" <This email address is being protected from spambots. You need JavaScript enabled to view it. >

- DKIM-Filter header. By default OpenDKIM puts it's own header. It took me a while to figure out that my messages are being flagged as spam not just because I started signing them with DKIM but because of this extra header:

DKIM-Filter: OpenDKIM Filter v2.11.0

To resolve it just ensure your DKIM signing software does not put it's own signature. In case of OpenDKIM you set 'SoftwareHeader' to 'no' in /etc/opendkim.conf

Once you have managed to get the messages delivered to Yahoo inbox you might want to consider applying to Yahoo Complaint Feedback Loop at:

https://help.yahoo.com/kb/sign-manage-yahoo-complaint-feedback-loop-program-sln3438.html

 

Outlook.com / hotmail.com spam classification

Or even better - messages are accepted but then silently dropped.

Based on experience those are more based on IP address filtering than content. Especially if you manage to get your emails delivered to Yahoo inbox which is quite fragile to content.

As a first step check the reputation on the following:

- Sorbs - this is covered by https://www.blacklist.ie/ check

- Symantec blaclistlis - manual check at https://ipremoval.sms.symantec.com/

- sender score at: https://senderscore.org/

If all above are fine then I would suggest just opening support ticket with Microsoft at: http://go.microsoft.com/fwlink/?LinkID=614866

You need to be honest in the support ticket, provide all information and be patient. Be prepared to reply as many times as needed (around 4-5 times) till you actually get to talk to some human. Do reply even if the reply is negative like:

We have completed reviewing the IP(s) you submitted. The following table contains the results of our investigation. Not qualified for mitigation

Once you have your IP address mitigated by Microsoft in order to maintain the reputation make sure you are monitoring emails coming from Microsoft Junk Email Report program:

https://postmaster.live.com/snds/JMRP.aspx

Those emails are coming from This email address is being protected from spambots. You need JavaScript enabled to view it. . Ensure it's whitelisted. You will be surprised to see what kind of emails are being marked as spam by some individuals. Just to mention valid invoices, payment confirmations or even payslips. It is a good practise in my opinion to create a rule that will reject emails going to any of those individuals after they mark your email as spam.

 

 

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