IT, Office365, Smart Home, PowerShell and Blogging Tips. Sender Policy Framework (SPF) allows email administrators to reduce sender-address forgery (spoofing) by specifying which are allowed to send email for a domain. Conditional Sender ID filtering: hard fail. Add a predefined warning message, to the E-mail message subject. All SPF TXT records end with this value. How to deal with a Spoof mail attack using SPF policy in Exchange-based environment, Exchange Online | Using the option of the spam filter policy, How to configure Exchange Online spam filter policy to mark SPF fail as spam, Implementing SPF Fail policy using Exchange Online rule (dealing with Spoof E-mail attack) | Phase 1 learning mode, Implementing SPF Fail policy using Exchange Online rule (dealing with Spoof E-mail attack) | Phase 2 production, Implementing SPF Fail policy using Exchange Online rule (dealing with Spoof E-mail attack) | Phase 1 learning mode | Part 2#3, Implementing SPF Fail policy using Exchange Online rule (dealing with Spoof E-mail attack) | Phase 2 production | part 3#3), Submit a request for removing your mail server IP from Office 365 black list, My E-mail appears as spam | Troubleshooting Mail server | Part 14#17, Detect spoof E-mail and add disclaimer using Exchange Online rule |Part 6#12, Create unlimited Client Secret in Azure AD, Configure Certificate Based Authentication to run automated PowerShell scripts, Implementing SPF Fail policy using Exchange Online rule (dealing with Spoof E-mail attack) | Introduction (this article), Case 1 a scenario in which the hostile element uses the spoofed identity of a, Case 2 a scenario in which the hostile element uses a spoofed identity of. The SPF mechanism doesnt perform and concrete action by himself. The receiving server may also respond with a non-delivery report (NDR) that contains an error similar to these: Some SPF TXT records for third-party domains direct the receiving server to perform a large number of DNS lookups. This list is known as the SPF record. Implement the SPF Fail policy using a two-phase procedure the learning/inspection phase and the production phase. For example: Having trouble with your SPF TXT record? But it doesnt verify or list the complete record. Add SPF Record As Recommended By Microsoft. Messages that hard fail a conditional Sender ID check are marked as spam. In case you wonder why I use the term high chance instead of definite chance is because, in reality, there is never 100% certainty scenario. Summary: This article describes how Microsoft 365 uses the Sender Policy Framework (SPF) TXT record in DNS to ensure that destination email systems trust messages sent from your custom domain. Export the content of Exchange mailbox Recoverable items folder to PST using the Office 365 content search | Step by step guide | 2#3, Detect spoof E-mail and mark the E-mail as spam using Exchange Online rule | Part 4#12, Connecting users to their Exchange Online mailbox Stage migration solving the mystery | Part 2#2 | Part 36#36. Include the following domain name: spf.protection.outlook.com. office 365 mail SPF Fail but still delivered Hello today i received mail from my organization. When you have created a new Office 365 tenant and your subscription includes Exchange Online or Teams, then you will need to add a couple of DNS records. To get started, see Use DKIM to validate outbound email sent from your custom domain in Microsoft 365. Nearly all large email services implement traditional SPF, DKIM, and DMARC checks. Some services have other, more strict checks, but few go as far as EOP to block unauthenticated email and treat them as spoofed messages. Instead, ensure that you use TXT records in DNS to publish your SPF information. The organization publishes an SPF record (implemented as TXT record) that includes information about the IP address of the mail servers, which are authorized to send an E-mail message on behalf of the particular domain name. However, anti-phishing protection works much better to detect these other types of phishing methods. In these examples, contoso.com is the sender and woodgrovebank.com is the receiver. Identify a possible miss configuration of our mail infrastructure. Now that Enhanced Filtering for Connectors is available, we no longer recommended turning off anti-spoofing protection when your email is routed through another service before EOP. Note: MailRoute will automatically recognize that you are using Office 365 for your outbound service, so you do not need to enter an outbound mailserver in the MailRoute Control Panel. Q5: Where is the information about the result from the SPF sender verification test stored? In reality, most of the organization will not implement such a strict security policy because they would prefer to avoid a false-positive scenario in which a legitimate mail mistakenly identified as Spoof mail. The sender identity can be any identity, such as the sender identity of a well-known organization/company, and in some cases; the hostile element is rude enough to use the identity of our organization for attacking one of our organization users (such as in spear phishing attack). What is the conclusion such as scenario, and should we react to such E-mail message? If you provided a sample message header, we might be able to tell you more. Normally you use the -all element which indicates a hard fail. If you have any questions, just drop a comment below. Outlook.com might then mark the message as spam. In case the mail server IP address that sends the E-mail on behalf of the sender, doesnt appear as authorized IP address in the SPF record, SPF sender verification test result is Fail. Vs. this scenario, in a situation in which the sender E-mail address includes our domain name, and also the result from the SPF sender verification test is fail, this is a very clear sign of the fact that the particular E-mail message has a very high chance to consider as Spoof mail. In the current article series, our primary focus will be how to implement an SPF policy for incoming mail, by using the option of Exchange rule, and not by using the Exchange Online spam filter policy option. LazyAdmin.nl is compensated for referring traffic and business to these companies at no expense to you. A wildcard SPF record (*.) For example, in case that we need to Impose a strict security policy, we will not be willing to take the risk, and in such scenario, we will block the E-mail message, send the E-mail to quarantine or forward the E-mail to a designated person that will need to examine the E-mail and decide if he wants to release the E-mail or not. The meaning is a hostile element that executes spoofing or Phishing attacks and uses a sender E-mail address that includes our domain name. I hate spam to, so you can unsubscribe at any time. Gather the information you need to create Office 365 DNS records, Troubleshooting: Best practices for SPF in Office 365, How SPF works to prevent spoofing and phishing in Office 365, Common. Enforcement rule is usually one of the following: Indicates hard fail. Scenario 1. We . . For instructions, see Gather the information you need to create Office 365 DNS records. First, we are going to check the expected SPF record in the Microsoft 365 Admin center. You can also specify IP address ranges using CIDR notation, for example ip4:192.168.0.1/26. The rest of this article uses the term SPF TXT record for clarity. Secondly, if your user has the sender's address added to their safe senders list, or sender address is in contacts + contacts are trusted, the message would skip spam filtering and be delivered to inbox. It doesn't have the support of Microsoft Outlook and Office 365, though. While there was disruption at first, it gradually declined. If you don't use a custom URL (and the URL used for Office 365 ends in onmicrosoft.com), SPF has already been set up for you in the Office 365 service. If a message exceeds the 10 limit, the message fails SPF. This option combines an SPF check with a Sender ID check to help protect against message headers that contain forged senders. You need all three in a valid SPF TXT record. The main purpose of SPF is to serve as a solution for two main scenarios: A Spoof mail attacks scenario, in which hostile element abuses our organizational identity, by sending a spoofed E-mail message to external recipients, using our organizational identity (our domain name). If the sender isn't permitted to do so, that is, if the email fails the SPF check on the receiving server, the spam policy configured on that server determines what to do with the message. It is true that Office 365 based environment support SPF but its imperative to emphasize that Office 365 (Exchange Online and EOP) is not configured anything automatically! The obvious assumption is that this is the classic scenario of Spoof mail attack and that the right action will be to block automatically or reject the particular E-mail message. SPF sender verification test fail | External sender identity. It's a first step in setting up the full recommended email authentication methods of SPF, DKIM, and DMARC. The reason for our confidence that the particular E-mail message has a very high chance to consider as Spoof mail is because we are the authority who is responsible for managing our mail infrastructure. We can certainly give some hints based on the header information and such, but it might as well be something at the backend (like the changes which caused the previous "incident"). Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. Off: The ASF setting is disabled. If it finds another include statement within the records for contoso.net or contoso.org, it will follow those too. No. For example, one of the most popular reasons for the result fail when using the SPF sender verification test is a problem or a miss configuration, in which the IP address of one of our mail server/services that our organization use, was not added to the SPF record. In this example, the SPF rule instructs the receiving email server to only accept mail from these IP addresses for the domain contoso.com: This SPF rule tells the receiving email server that if a message comes from contoso.com, but not from one of these three IP addresses, the receiving server should apply the enforcement rule to the message. Join the movement and receive our weekly Tech related newsletter. Feb 06 2023 document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); LazyAdmin.nl is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. As mentioned, the SPF sender verification test just stamp the E-mail message with information about the SPF test result. Depending on the property, ASF detections will either mark the message as Spam or High confidence spam. Authentication-Results: spf=none (sender IP is 118.69.226.171) smtp.mailfrom=kien.ngan; thakrale5.onmicrosoft.com; dkim=none (message not signed) header.d=none;thakrale5.onmicrosoft.com; dmarc=none action=none header.from=thakrale5.onmicrosoft.com; Received-SPF: None (protection.outlook.com: kien.ngan does not designate permitted sender hosts) For more information, see Configure anti-spam policies in EOP. SPF identifies which mail servers are allowed to send mail on your behalf. The following Mark as spam ASF settings set the SCL of detected messages to 6, which corresponds to a Spam filter verdict and the corresponding action in anti-spam policies. This record works for just about everyone, regardless of whether your Microsoft datacenter is located in the United States, or in Europe (including Germany), or in another location. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. SPF validates the origin of email messages by verifying the IP address of the sender against the alleged owner of the sending domain. By analyzing the information thats collected, we can achieve the following objectives: 1. The answer is that as always; we need to avoid being too cautious vs. being too permissive. Creating multiple records causes a round robin situation and SPF will fail. Keep in mind, that SPF has a maximum of 10 DNS lookups. Domain names to use for all third-party domains that you need to include in your SPF TXT record. DMARC email authentication's goal is to make sure that SPF and DKIM information matches the From address. Can we say that we should automatically block E-mail message which their organization doesnt support the use of SPF? However, the industry is becoming more aware about issues with unauthenticated email, particularly because of the problem of phishing. Best thing to do is report the message via the Junk add-in and open a support case to have it properly investigated. If you have anti-spoofing enabled and the SPF record: hard fail ( MarkAsSpamSpfRecordHardFail) turned on, you will probably get more false positives. Read Troubleshooting: Best practices for SPF in Office 365. We recommend the value -all. by adkim . If you're not sure that you have the complete list of IP addresses, then you should use the ~all (soft fail) qualifier. More info about Internet Explorer and Microsoft Edge. Instead of immediately deleting such E-mail items, the preferred option is to redirect this E-mail to some isolated store such as quarantine. There is no right answer or a definite answer that will instruct us what to do in such scenarios. Messages that contain numeric-based URLs (typically, IP addresses) are marked as spam. Keeping track of this number will help prevent messages sent from your organization from triggering a permanent error, called a perm error, from the receiving server. Once you've formed your record, you need to update the record at your domain registrar. What is SPF? For a list of domain names you should include for Microsoft 365, see External DNS records required for SPF. @tsulaI solved the problem by creating two Transport Rules. This is no longer required. Mark the message with 'soft fail' in the message envelope. The only thing that we can do is enable other organizations that receive an email message that has our domain name, the ability to verify if the E-mail is a legitimate E-mail message or not. You will first need to identify these systems because if you dont include them in the SPF record, mail sent from those systems will be listed as spam. For example, vs. the Exchange Online spam filter policy that marks every incoming E-mail message that has the value of SPF = Fail as spam mail without distinction, when using the option of Exchange rule, we can define a more refined version of this scenario, a condition in which only if the sender uses our domain name + the result from the SPF verification test is Fail, only, then the E-mail message will be identified as Spoof mail. For example: Once you've formulated your SPF TXT record, follow the steps in Set up SPF in Microsoft 365 to help prevent spoofing to add it to your domain. In the next two articles (Implementing SPF Fail policy using Exchange Online rule (dealing with Spoof E-mail attack) | Phase 1 learning mode | Part 2#3 and Implementing SPF Fail policy using Exchange Online rule (dealing with Spoof E-mail attack) | Phase 2 production | part 3#3), we will review in details the implementation of SPF fail policy by using an Exchange Online rule. This is the default value, and we recommend that you don't change it. Also, if you're only using SPF, that is, you aren't using DMARC or DKIM, you should use the -all qualifier. You will need to create an SPF record for each domain or subdomain that you want to send mail from. You can't report messages that are filtered by ASF as false positives. For example, 131.107.2.200. For example, let's say that your custom domain contoso.com uses Office 365. You don't need to configure this setting in the following environments, because legitimate NDRs are delivered, and backscatter is marked as spam: In standalone EOP environments that protect inbound email to on-premises mailboxes, turning this setting on or off has the following result: More info about Internet Explorer and Microsoft Edge, Microsoft Defender for Office 365 plan 1 and plan 2. Setting up DMARC for your custom domain includes these steps: Step 1: Identify valid sources of mail for your domain. Refresh the DNS records page in Microsoft 365 Admin Center to verify the settings.The status of the TXT record will be listed as Ok when you have configured it correctly. For example, if you are hosted entirely in Office 365, that is, you have no on-premises mail servers, your SPF TXT record would include rows 1, 2, and 7 and would look like this: The example above is the most common SPF TXT record. How Does An SPF Record Prevent Spoofing In Office 365? Not all phishing is spoofing, and not all spoofed messages will be missed.