Add a predefined warning message, to the E-mail message subject. If it finds another include statement within the records for contoso.net or contoso.org, it will follow those too. If all of your mail is sent by Microsoft 365, use this in your SPF TXT record: In a hybrid environment, if the IP address of your on-premises Exchange Server is 192.168.0.1, in order to set the SPF enforcement rule to hard fail, form the SPF TXT record as follows: If you have multiple outbound mail servers, include the IP address for each mail server in the SPF TXT record and separate each IP address with a space followed by an "ip4:" statement. This article describes how to update a Domain Name Service (DNS) record so that you can use Sender Policy Framework (SPF) email authentication with your custom domain in Office 365. Phishing emails Fail SPF but Arrive in Inbox Posted by enyr0py 2019-04-23T19:01:42Z. Basically, SPF, along with DKIM, DMARC, and other technologies supported by Office 365, help prevent spoofing and phishing. This is the scenario in which we get a clear answer regarding the result from the SPF sender verification test the SPF test fail! Mark the message with 'hard fail' in the message envelope and then follow the receiving server's configured spam policy for this type of message. Need help with adding the SPF TXT record? 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. Identify a possible miss configuration of our mail infrastructure. Once a message reaches this limit, depending on the way the receiving server is configured, the sender may get a message that says the message generated "too many lookups" or that the "maximum hop count for the message has been exceeded" (which can happen when the lookups loop and surpass the DNS timeout). today i received mail from my organization. For information about the domains you'll need to include for Microsoft 365, see External DNS records required for SPF. ip6 indicates that you're using IP version 6 addresses. See You don't know all sources for your email. For example, if you are hosted entirely in Office 365 Germany, that is, you have no on-premises mail servers, your SPF TXT record would include rows 1, 4, and 7 and would look like this: If you're already deployed in Office 365 and have set up your SPF TXT records for your custom domain, and you're migrating to Office 365 Germany, you need to update your SPF TXT record. SPF is configured by adding a specially formatted TXT record to the DNS zone for the domain. An SPF TXT record is a DNS record that helps prevent spoofing and phishing by verifying the domain name from which email messages are sent. Messages that contain numeric-based URLs (typically, IP addresses) are marked as spam. The main reason that I prefer to avoid the option of using the Exchange Online spam filter option is because, this option doesnt distinguish between a scenario in which the sender uses our domain name as part of his E-mail address vs. a scenario in which the sender uses E-mail address, which doesnt include our domain name. This ASF setting is no longer required. Gather this information: The SPF TXT record for your custom domain, if one exists. Sender Policy Framework (SPF) allows email administrators to reduce sender-address forgery (spoofing) by specifying which are allowed to send email for a domain. It's a first step in setting up the full recommended email authentication methods of SPF, DKIM, and DMARC. Messages that contain web bugs are marked as high confidence spam. This phase is described as learning mode or inspection mode because the purpose of this step has been just to identify an event of a Spoof mail attack in which the hostile element uses an E-mail address that includes our domain name + Log this information. If you haven't already done so, form your SPF TXT record by using the syntax from the table. EOP includes a default spam filter policy, which includes various options that enable us to harden the existing mail security policy. Did you know you can try the features in Microsoft 365 Defender for Office 365 Plan 2 for free? Great article. Q10: Why our mail server doesnt automatically block incoming E-mail that has the value of SPF = Fail? Login at admin.microsoft.com, Expand Settings and select Domains Select your custom Domain (not the .onmicrosoft.com domain, Click on the DNS Records tab.If you have bought a license that includes Exchange Online then the required Office 365 SPF record will be shown here, Click on the TXT (SPF) record to open it. This is the default value, and we recommend that you don't change it. We don't recommend that you use this qualifier in your live deployment. 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. Best thing to do is report the message via the Junk add-in and open a support case to have it properly investigated. SPF identifies which mail servers are allowed to send mail on your behalf. 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). Add a new Record Select Type: TXT Name/Host: @ Content/Value: v=spf1 include:spf.protection.outlook.com -all (or copy paste it from Microsoft 365 ( step 4 )) Click SaveContinue at Step 8, If you already have an SPF record, then you will need to edit it. Think of your scanners that send email to external contacts, (web)applications, newsletters systems, etc. For a list of domain names you should include for Microsoft 365, see External DNS records required for SPF. All SPF TXT records end with this value. Typically, email servers are configured to deliver these messages anyway. A wildcard SPF record (*.) If you are a small business, or are unfamiliar with IP addresses or DNS configuration, call your Internet domain registrar (ex. Hope this helps. This type of configuration can lead us to many false-positive events, in which E-mail message that sent from our customer or business partner can be identified as spam mail. Next, see Use DMARC to validate email in Microsoft 365. Q2: Why does the hostile element use our organizational identity? SPF is added as a TXT record that is used by DNS to identify which mail servers can send mail on behalf of your custom domain. In the next article, Implementing SPF Fail policy using Exchange Online rule (dealing with Spoof E-mail attack) | Phase 1 learning mode | Part 2#3, we will review the step-by-step instruction needed to create an Exchange Online rule that will help us to monitor such events. Not all phishing is spoofing, and not all spoofed messages will be missed. Attackers will adapt to use other techniques (for example, compromised accounts or accounts in free email services). 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. You intend to set up DKIM and DMARC (recommended). To be able to react to the SPF events such as SPF = none (a scenario in which the domain doesnt include a dedicated SPF record) or a scene of SPF = Fail (a scene in which the SPF sender verification test failed), we will need to define a written policy that will include our desirable action + configure our mail infrastructure to use this SPF policy.. Legitimate newsletters might use web bugs, although many consider this an invasion of privacy. Even when we get to the production phase, its recommended to choose a less aggressive response. A typical SPF TXT record for Microsoft 365 has the following syntax: text v=spf1 [<ip4>|<ip6>:<IP address>] [include:<domain name>] <enforcement rule> For example: text v=spf1 ip4:192.168..1 ip4:192.168..2 include:spf.protection.outlook.com -all where: v=spf1 is required. This is because the receiving server cannot validate that the message comes from an authorized messaging server. It's important to note that you need to create a separate record for each subdomain as subdomains don't inherit the SPF record of their top-level domain. LazyAdmin.nl also participates in affiliate programs with Microsoft, Flexoffers, CJ, and other sites. SPF works best when the path from sender to receiver is direct, for example: When woodgrovebank.com receives the message, if IP address #1 is in the SPF TXT record for contoso.com, the message passes the SPF check and is authenticated. We are going to start with looking up the DNS records that Microsoft 365 is expecting and then add the correct SPF record to our DNS hosting provider: First, we are going to check the expected SPF record in the Microsoft 365 Admin center. For example, at the time of this writing, Salesforce.com contains 5 include statements in its record: To avoid the error, you can implement a policy where anyone sending bulk email, for example, has to use a subdomain specifically for this purpose. If you don't have a deployment that is fully hosted in Microsoft 365, or you want more information about how SPF works or how to troubleshoot SPF for Microsoft 365, keep reading. To avoid this, you can create separate records for each subdomain. Read the article Create DNS records at any DNS hosting provider for Microsoft 365 for detailed information about usage of Sender Policy Framework with your custom domain in Microsoft 365. Soft fail. However, your risk will be higher. The simple truth is that we cannot prevent this scenario because we will never be able to have control over the external mail infrastructure that is used by these hostile elements. However, because anti-spoofing is based upon the From address in combination with the MAIL FROM or DKIM-signing domain (or other signals), it's not enough to prevent SRS forwarded email from being marked as spoofed. Getting Started with PDQ Deploy & Inventory, Automatically assign licenses in Office 365, Match all domain name records (A and AAAA), Match all listed MX records. You can only create one SPF TXT record for your custom domain. Messages that hard fail a conditional Sender ID check are marked as spam. Sender Policy Framework, or SPF, is an email authentication technique that helps protect email senders and recipients from spam, phishing and spoofing. No. The second one reads the "Authentication-Results" line in the header information and if it says "Fail" sends the email to quarantine. One option that is relevant for our subject is the option named SPF record: hard fail. Scenario 1 the sender uses an E-mail address that includes a domain name of a well-known organization. In addition to IP addresses, you can also configure your SPF TXT record to include domains as senders. 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. Email advertisements often include this tag to solicit information from the recipient. 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. Add SPF Record As Recommended By Microsoft. One drawback of SPF is that it doesn't work when an email has been forwarded. 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. The protection layers in EOP are designed work together and build on top of each other. If you're already familiar with SPF, or you have a simple deployment, and just need to know what to include in your SPF TXT record in DNS for Microsoft 365, you can go to Set up SPF in Microsoft 365 to help prevent spoofing. Instead, the E-mail message will be forwarded to a designated authority, such as IT person, that will get the suspicious E-mail, and this person will need to carefully examine the E-mail and decide if the E-mail is indeed spoofed E-mail or a legitimate E-mail message that mistakenly identified as Spoof mail. The event in which the SPF sender verification test result is Fail, can be realized in two main scenarios. Learn about who can sign up and trial terms here. The SPF mechanism doesnt perform and concrete action by himself. From my experience, the phase is fascinating because after we activate the monitor process, we will usually find an absorbing finding of: Based on this information, we will be able to understand the real scope of the problem, the main characters of this attack and so on. The SPF -all mechanism denotes SPF hardfail (emails that fail SPF will not be delivered) for emails that do not pass SPF check and is the recommended . Messages with no subject, no content in the message body, and no attachments are marked as high confidence spam. However, there are some cases where you may need to update your SPF TXT record in DNS. Office 365 supports only one SPF record (a TXT record that defines SPF) for your domain. To be able to use the SPF option we will need to implement by ourselves the following proceeds: Add to the DNS server that hosts our domain name the required SPF record, and verifies that the syntax of the SPF record is correct + verify that the SPF record includes information about all the entities that send an E-mail message on behalf of our domain name. Yes. Take a look at the basic syntax for an SPF rule: For example, let's say the following SPF rule exists for contoso.com: v=spf1 . Learning about the characters of Spoof mail attack. This option described as . 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. For instructions, see Gather the information you need to create Office 365 DNS records. Messages sent from an IP address that isn't specified in the SPF Sender Policy Framework (SPF) record in DNS for the source email domain are marked as high confidence spam. If you have a custom domain or are using on-premises Exchange servers along with Microsoft 365, you need to manually set up DMARC for your outbound mail. For advanced examples and a more detailed discussion about supported SPF syntax, see How SPF works to prevent spoofing and phishing in Office 365. . In case we decide to activate this option, the result is that each of the incoming E-mails accepted by our Office 365 mail server (EOP), and that include SPF sender verification results of SPF = Fail, will automatically be marked as spam mail. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. and are the IP address and domain of the other email system that sends mail on behalf of your domain. For questions and answers about anti-spam protection, see Anti-spam protection FAQ. This improved reputation improves the deliverability of your legitimate mail. Failing SPF will not cause Office 365 to drop a message, at best it will mark it as Junk, but even that wont happen in all scenarios. When Microsoft enabled this feature in 2018, some false positives happened (good messages were marked as bad). Other options are: I will give you a couple of examples of SPF records, so you have an idea of how they look when you combine different applications. The reason that I prefer the option of Exchange rule is, that the Exchange rule is a very powerful tool that can be used to define a Tailor-made SPF policy that will suit the specific structure and the needs of the organization. Some services have other, more strict checks, but few go as far as EOP to block unauthenticated email and treat them as spoofed messages. What are the possible options for the SPF test results? 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. Once you've formed your record, you need to update the record at your domain registrar. SPF is added as a TXT record that is used by DNS to identify which mail servers can send mail on behalf of your custom domain. If the receiving server finds out that the message comes from a server other than the Office 365 messaging servers listed in the SPF record, the receiving mail server can choose to reject the message as spam. 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). The enforcement rule is usually one of these options: Hard fail. Solved Microsoft Office 365 Email Anti-Spam. You need all three in a valid SPF TXT record. You can identify messages that were filtered by ASF by: The following sections describe the ASF settings and options that are available in anti-spam policies in the Microsoft 365 Defender portal, and in Exchange Online PowerShell or standalone EOP PowerShell (New-HostedContentFilterPolicy and Set-HostedContentFilterPolicy). More info about Internet Explorer and Microsoft Edge. Note: Suppose we want to be more accurate, this option is relevant to a scenario in which the SPF record of the particular domain is configured with the possibility of SPF hard fail. If you're the sender's email admin, make sure the SPF records for your domain at your domain registrar are set up correctly. For example: Previously, you had to add a different SPF TXT record to your custom domain if you were using SharePoint Online. SPF enables receiving mail servers to authenticate whether an email message was sent from an authorized mail server - but only when the domain owner's SPF record is valid. Microsoft believes that the risk of continuing to allow unauthenticated inbound email is higher than the risk of losing legitimate inbound email. This applies to outbound mail sent from Microsoft 365. For tips on how to avoid this, see Troubleshooting: Best practices for SPF in Microsoft 365. If you're not sure that you have the complete list of IP addresses, then you should use the ~all (soft fail) qualifier. The first one reads the "Received-SPF" line in the header information and if it says "SPF=Fail" it sends the message to quarantine. The enforcement rule indicates what the receiving mail system should do with mail sent from a server that isnt listed in the SPF record. We recommend the value -all. By rewriting the SMTP MAIL FROM, SRS can ensure that the forwarded message passes SPF at the next destination. One option that is relevant for our subject is the option named SPF record: hard fail. We do not recommend disabling anti-spoofing protection. This change should reduce the risk of SharePoint Online notification messages ending up in the Junk Email folder. In this phase, we will need to decide what is the concrete action that will apply for a specific E-mail message that will identify a Spoof mail (SPF = Fail). 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. Nearly all large email services implement traditional SPF, DKIM, and DMARC checks. 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. So only the listed mail servers are allowed to send mail, A domain name that is allowed to send mail on behalf of your domain, Ip address that is allowed sending mail on behalf of your domain, ip4:21.22.23.24 or complete range: ip4:20.30.40.0/19, Indicates what to do with mail that fails, Sending mail for on-premise systems public IP Address 213.14.15.20, Sending mail from MailChimp (newsletters service). DMARC email authentication's goal is to make sure that SPF and DKIM information matches the From address. The E-mail address of the sender uses the domain name of a well-known bank. In each of the above scenarios, the event in which the SPF sender verification test ended with SPF = Fail result is not good. We . Use the step-by-step instructions for updating SPF (TXT) records for your domain registrar. To do this, change include:spf.protection.outlook.com to include:spf.protection.outlook.de. This phase can describe as the active phase in which we define a specific reaction to such scenarios. A hard fail, for example, is going to look like this: v=spf1 ip4 192.xx.xx.xx -all If mail is being sent from another server that's not the IP in the SPF, the receiving server will discard it. More info about Internet Explorer and Microsoft Edge, Microsoft Defender for Office 365 plan 1 and plan 2, Set up SPF in Microsoft 365 to help prevent spoofing, Troubleshooting: Best practices for SPF in Microsoft 365, Example: SPF TXT record for multiple outbound on-premises mail servers and Microsoft 365, Use DKIM to validate outbound email sent from your custom domain in Microsoft 365, Use DMARC to validate email in Microsoft 365, Create DNS records at any DNS hosting provider for Microsoft 365. SPF identifies which mail servers are allowed to send mail on your behalf. Q9: So how can I activate the option to capture events of an E-mail message that have the value of SPF = Fail? If you do not use any external third-party email services and route all your emails via Office 365, your SPF record will have the following syntax: v=spf1 include:spf.protection.outlook.com -all. SPF helps validate outbound email sent from your custom domain (is coming from who it says it is). Join the movement and receive our weekly Tech related newsletter. You can read a detailed explanation of how SPF works here. What is SPF? Also, if your custom domain does not have an SPF TXT record, some receiving servers may reject the message outright. Your email address will not be published. Received-SPF: Fail ( protection.outlook.com: domain of ourdomain1.com does not designate X .X.X.X as permitted sender) We have SPF for our domain v=spf1 include:spf.protection.outlook.com -all We have also enable that fail SPF email should not get in our admin centre. 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. The SPF sender verification can mark a particular E-mail message with a value to SPF = none or SPF = Fail. In other words, using SPF can improve our E-mail reputation. For example, contoso.com might want to include all of the IP addresses of the mail servers from contoso.net and contoso.org, which it also owns. A great toolbox to verify DNS-related records is MXToolbox. This article provides frequently asked questions and answers about anti-spoofing protection for Microsoft 365 organizations with mailboxes in Exchange Online, or standalone Exchange Online Protection (EOP) organizations without Exchange Online mailboxes. To do this, contoso.com publishes an SPF TXT record that looks like this: When the receiving server sees this record in DNS, it also performs a DNS lookup on the SPF TXT record for contoso.net and then for contoso.org. Even in a scenario in which the mail infrastructure of the other side support SPF, in case that the SPF verification test marked as Fail, we cannot be sure that the spoofed E-mail will be blocked. Usually, this is the IP address of the outbound mail server for your organization. This is where we use the learning/inspection mode phase and use it as a radar that helps us to locate anomalies and other infrastructure security issues. For example in Exchange-based environment, we can add an Exchange rule that will identify SPF failed events, and react to this type of event with a particular action such as alert a specially designated recipient or block the E-mail message. Creating multiple records causes a round robin situation and SPF will fail. Do nothing, that is, don't mark the message envelope. The reason could be a problem with the SPF record syntax, a specific mail flow, such as E-mail forwarding that leads to this result, and so on. But it doesnt verify or list the complete record. SPF records in Office 365 are DNS records that help authenticate Office 365 based emails so organizations can operate with higher levels of trust and prevent spoofing. 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. The setting is located at Exchange admin Center > protection > spam filter > double click Default > advanced options > set SPF record: hard fail: off. Implement the SPF Fail policy using a two-phase procedure the learning/inspection phase and the production phase. Indicates neutral. However, anti-phishing protection works much better to detect these other types of phishing methods. For more information, see Configure anti-spam policies in EOP. Exchange Online (EOP), include spam filter policy, which contains many security settings that are disabled by default and can be activated manually based on the particular mail security policy that the organization wants to implement. The Exchange incident report includes a summary of the specific mail flow, such as the name of the sender, recipient, and the Exchange rule that was activated and also; we can ask to include an attachment of the original E-mail message that was captured..