my e-mail appears as spam | the 7 major reasons | part 6#17

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Page 1 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17 Written by Eyal Doron | o365info.com MY E-MAIL APPEARS AS SPAM | THE 7 MA JOR REASONS | PART 6#17 The current article is the continuation of the former article (My E- mail appears as spam | The 7 major reasons | Part 5#17) in which we continue to review the major reasons, that could lead to a scenario in which E-mail that is sent from our organization, identified as spam E- mail. In the current article we will review the following causes: False positive User Desktop malware “Problematic” Website 4. False positive

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My E-mail appears as spam | The 7 major reasons | Part 6#17 http://o365info.com/my-e-mail-appears-as-spam-the-7-major-reasons-part-6-17 Review three major reasons, that could lead to a scenario, in which E-mail that is sent from our organization identified as spam mail: 4. False positive, 5. User Desktop malware, 6. “Problematic” Website Eyal Doron | o365info.com

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Page 1 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

MY E-MAIL APPEARS AS SPAM | THE 7

MA JOR REASONS | PART 6#17

The current article is the continuation of the former article (My E-

mail appears as spam | The 7 major reasons | Part 5#17) in which

we continue to review the major reasons, that could lead to a

scenario in which

E-mail that is sent from our organization, identified as spam E-

mail.

In the current article we will review the following causes:

False positive

User Desktop malware

“Problematic” Website

4. False positive

Page 2 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

Regarding the subject of internal \ outbound spam, the term “false

positive”, relate to a scenario in which a legitimate E-mail is

recognized by mistake as a spam\junk mail.

Q: Is there an option to completely avoid from a scenario of “false

positive”?

A: Sadly, the answer is no. There are different “elements”, which can

identify our organization E-mail by mistake as a spam\junk mail.

For example, your E-mail message could be mistakenly classified as

spam\junk mail by a blacklist provider who recognizes aspects in

your E-mail message that “look like” charters of spam\junk mail (no

system is perfect).

Another example could be: destination recipient looks at your E-mail

message, and it seemed to him like a spam\junk mail.

For this reason, he decides to report the specific E-mail message as

spam\junk mail.

Page 3 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

In the following diagram, we can see that there could be “additional

element” that could “decide” to identify a specific E-mail as

spam\junk mail such as – the user mail application or the security

application that is installed on the user desktop.

How to avoid?

There is no real method for “avoiding” this scenario. In case that

legitimate E-mail that was sent by organization users is classified as

spam\junk E-mail by a specific blacklist, all we can do is to address

the specific blacklist owner and ask to be removed from the blacklist.

Another best practice could be: implement a procedure, in which we

check the “spam score” of commercial E-mail, before we send the

specific E-mail message to the large group of recipients.

Page 4 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

You can read more information about the option of testing your

spam score in the article: My E-mail appears as spam | The 7

major reasons | Part 5#17

5. User Desktop malware

In case that the user desktop is infected with Malware (virus,

spyware, etc.) the result can be a “stranger phenomenon” such as:

mail that disappears, spam mail that sends from our organization

recipient without his knowledge and so on.

One of the major charters of such a scenario (a scenario in which the

user desktop is infected by Malware) is that the organization user is

not aware that spam E-mail is sent by his name to other recipients.

The “point” in which we become aware of this issue, is only if the

destination mail server reply using the NDR message or worse

scenario, in which our organization appears as blacklisted.

Page 5 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

In a scenario of an “NDR”, it’s easy to implement the reverse

engineering process in which we understand that the problem is

related to a specific recipient organization.

In a scenario in which the “destination mail server” doesn’t reply

using NDR or, in a scenario in which we found that our organization

is blacklisted, there is no thread or “bread cramp” that could lead us

to the “source of the problem”.

Q: How to recognize a scenario in which a user’s desktop is infected

with Malware that sends an E-mail message on behalf of the user?

A: There is no “magic formula” that will help you to capture this type

of scenario. Our main “weapons” is the awareness for the charters of

this type of scenarios (in which the user desktop is compromised by

malware that send spam E-mail on behalf of the organization user).

One of the main charters for this type of scenario is “lack of

coordination” between the evidence that exists in the user mailbox

versus the “evidence” that exists in the Exchange Online mail server.

For example – an organization’s user report about a strange

phenomenon in which he gets the NDR message for E-mail that he

didn’t send. The NDR message informs him that his E-mail was

rejected by the destination mail server because he was identified as

spam\junk mail.

Note – there is another spam scenario that has similar characteristics

named: NDR backscatter. In this scenario, the organization users get an

NDR message that informs them that their “destination recipient” doesn’t

exist.

This is a scenario in which a spammer impersonated himself to a

legitimate user from using our organization user identity.

Page 6 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

When we start to investigate this strange issue by looking at the user

mailbox and, in particular in the Sent mail folder, we cannot see any

evidence to the mail that was sent from the user mailbox.

The reason for this strange phenomenon is that most of the time, the

malware will prefer to “cover his track” by deleting the E-mail that he

sent from the sent item’s folder or by connecting the mail server

directly and bypassing the desktop mail client.

The phenomenon becomes even stranger when we look at our

Exchange Online message trace log and finds out, that the Exchange

Online log includes information about dozens or even hundreds of E-

mail messages that was sent by the specific organization user.

This scenario is a clear evidence of a scenario of Malware that took

over the user desktop and impersonate as a legitimate organization

user.

Q: How to avoid a scenario in which organization user desktop can

be compromised?

A: Verify that you implemented the basic security best practices that

relate to the user desktop security:

Page 7 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

Verify that the desktop includes installation of antivirus software.

Verify the antivirus software include all the last updates.

Verify the antivirus software service is turned on.

Another option:

Reset the organization user password

Monitor the “problematic user” activity by using the Exchange Online

message trace log.

For example, look at the Exchange Online log and try to locate a

“strange behavior” in which there are many E-mails that are sent “by the

user” to unknown E-mail address.

6. “Problematic” Website

Another interesting and unknown reason for classifying E-mail as a

spam\junk mail is related to the website address (URL) that appears

in E-mail message.

Exchange Online and other mail server are using the services of a

special blacklist provider, such as: surbl that specialized is a specific

“realm” that is focused on a URL address that considers is

“problematic URL address” and that appear in a user E-mail message.

Attached a quotation from the surbl website:

SURBLs are lists of web sites that have appeared in unsolicited

messages. Unlike most lists, SURBLs are not lists of message

senders.

I have read the information in the website that explains the method

that is used and I must admit, that I’m sure that I completely

Page 8 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

understand the full concept of the “methods” that are used by the

surbl service.

As I understand it, the first step that is implemented by the surbl

service is to – create a list of public websites that their name (their

URL address) appears in E-mails that was classified or identified as

spam\junk mail.

The fact that a specific website URL address “appear” in unsolicited E-

mail messages, “stamp” this website “suspicious”.

In case that user sends an E-mail message, which includes the URL

address of a website that appeared on the list of “suspicious web

site”, the E-mail message could be considered as mail item that

contains spam content.

Additional reading

SURBL

Page 9 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

NON-OFFICE 365 AND EXCHANGE ONLINE

ISSUES

Under the subject of – “factors and element that can lead into a

scenario in which E-mail that is sent from your organization could be

identified as spam\junk mail” there could be additional causes that

we didn’t review.

The reason that we have not reviewed these factors is – because that

in Office 365 and Exchange Online this factor cannot be realized.

An example of such causes could be:

A mail server that is hacked by spammers, mail server that

configured as: open relay, Mail application that doesn’t use standard

or non-RFC complaint SMTP protocol, missing MX record, missing

PTR records, using a dynamic IP address as the IP address of the mail

server and more.

Although in Office 365 and Exchange Online we should not be

concerned about the above issues, in case that we manage a “private

mail infrastructure” it’s important to be aware of this potential

problem.

Additional reading

Open mail relay

Email Fundamentals: What is an Open Relay?

The return of the open relays

What is SMTP relay?

Page 10 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

Internal \ outbound spam in Office 365

environment | Article series index

A quick reference for the article series

My E-mail appears as a spam | Article

series index | Part 0#17

The article index of the complete

article series

Introduction to the concept of internal \ outbound spam in general

and in Office 365 and Exchange Online environment

My E-mail appears as a spam –

Introduction | Office 365 | Part 1#17

The psychological profile of the

phenomenon: “My E-mail appears as

a spam!”, possible factors for causing

our E-mail to appear a “spam mail”,

the definition of internal \ outbound

spam.

Internal spam in Office 365 –

Introduction | Part 2#17

Review in general the term: “internal \

outbound spam”, miss conceptions

that relate to this term, the risks that

are involved in this scenario,

outbound spam E-mail policy and

more.

Page 11 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

Internal spam in Office 365 –

Introduction | Part 3#17

What are the possible reasons that

could cause to our mail to appear as

spam\junk mail, who or what are this

“elements”, that can decide that our

mail is a spam mail?, what are the

possible “reactions” of the destination

mail infrastructure that identify our E-

mail as spam\junk mail?.

Commercial E-mail – Using the right

tools | Office 365 | Part 4#17

What is commercial E-mail?

Commercial E-mail as part of the

business process. Why do I think that

Office 365\ Exchange Online is

unsuitable for the purpose of

commercial E-mail?

Introduction if the major causes for a scenario in which your

organization E-mail appears as spam

My E-mail appears as spam | The 7

major reasons | Part 5#17

Review three major reasons, that

could lead to a scenario, in which E-

mail that is sent from our

organization identified as spam mail:

1. E-mail content, 2. Violation of the

SMTP standards, 3. Bulk\Mass mail

Page 12 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

My E-mail appears as spam | The 7

major reasons | Part 6#17

Review three major reasons, that

could lead to a scenario, in which E-

mail that is sent from our

organization identified as spam mail:

4. False positive, 5. User Desktop

malware, 6. “Problematic” Website

Introduction if the subject of SPF record in general and in Office

365 environment

What is SPF record good for? | Part

7#17

The purpose of the SPF record and the

relation to for our mail infrastructure.

How does the SPF record enable us to

prevent a scenario in which hostile

elements could send E-mail on our

behalf.

Implementing SPF record | Part 8#17

The “technical side” of the SPF record:

the structure of SPF record, the way

that we create SPF record, what is the

required syntax for the SPF record in

an Office 365 environment + mix mail

environment, how to verify the

existence of SPF record and so on.

Page 13 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

Introduction if the subject of Exchange Online - High Risk Delivery

Pool

High Risk Delivery Pool and Exchange

Online | Part 9#17

How Office 365 (Exchange Online) is

handling a scenario of internal \

outbound spam by using the help of

the Exchange Online- High Risk

Delivery Pool.

High Risk Delivery Pool and Exchange

Online | Part 10#17

The second article about the subject

of Exchange Online- High Risk

Delivery Pool.

The troubleshooting path of internal \ outbound spam scenario

My E-mail appears as spam –

Troubleshooting path | Part 11#17

Troubleshooting scenario of internal \

outbound spam in Office 365 and

Exchange Online environment.

Verifying if our domain name is

blacklisted, verifying if the problem is

related to E-mail content, verifying if

the problem is related to specific

organization user E-mail address,

moving the troubleshooting process

to the “other side.

Page 14 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

My E-mail appears as spam |

Troubleshooting – Domain name and

E-mail content | Part 12#17 Verify if

our domain name appears as

blacklisted, verify if the problem

relates to a specific E-mail message

content, registering blacklist

monitoring services, activating the

option of Exchange Online outbound

spam.

My E-mail appears as spam |

Troubleshooting – Mail server | Part

13#17

What is the meaning of: “our mail

server”?, Mail server IP, host name

and Exchange Online. One of our

users got an NDR which informs him,

that his mail server is blacklisted!,

How do we know that my mail server

is blacklisted?

My E-mail appears as spam |

Troubleshooting – Mail server | Part

14#17

The troubleshooting path logic. Get

the information from the E-mail

message that was identified as

spam\NDR. Forwarding a copy of the

NDR message or the message that

saved to the junk mail

Page 15 of 15 | My E-mail appears as spam | The 7 major reasons | Part 6#17

Written by Eyal Doron | o365info.com

My E-mail appears as spam |

Troubleshooting – Mail server | Part

15#17

Step B – Get information about your

Exchange Online infrastructure, Step

C – fetch the information about the

Exchange Online IP address, Step D –

verify if the “formal “Exchange Online

IP address a

De-list your organization from a

blacklist | My E-mail appears as spam

| Part 16#17

Review the charters of a scenario in

which your organization appears as

blacklisted. The steps and the

operations that need to be

implemented for de-list your

organization from a blacklist.

Summery and recap of the troubleshooting and best practices in a

scenario of internal \ outbound spam

Dealing and avoiding internal spam |

Best practices | Part 17#17

Provide a short checklist for all the

steps and the operation that relates

to a scenario of – internal \ outbound

spam.