In all Microsoft 365 organizations, the Advanced Spam Filter (ASF) settings in anti-spam policies in EOP allow admins to mark messages as spam based on specific message properties. Q8: Who is the element which is responsible for alerting users regarding a scenario in which the result of the SPF sender verification test is Fail? Suppose a phisher finds a way to spoof contoso.com: Since IP address #12 isn't in contoso.com's SPF TXT record, the message fails the SPF check and the receiver may choose to mark it as spam. Specifically, the Mail From field that . Also, if you're only using SPF, that is, you aren't using DMARC or DKIM, you should use the -all qualifier. What is the conclusion such as scenario, and should we react to such E-mail message? Share. The first one reads the "Received-SPF" line in the header information and if it says "SPF=Fail" it sends the message to quarantine. 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. EOP includes a default spam filter policy, which includes various options that enable us to harden the existing mail security policy. Messages that hard fail a conditional Sender ID check are marked as spam. Learning/inspection mode | Exchange rule setting. If you provided a sample message header, we might be able to tell you more. The interesting thing is that in Exchange-based environment, we can use very powerful Exchange server feature named- Exchange rule, for identifying an event in which the SPF sender verification test result is Fail, and define a response respectively. It doesn't have the support of Microsoft Outlook and Office 365, though. The number of messages that were misidentified as spoofed became negligible for most email paths. Depending on the property, ASF detections will either mark the message as Spam or High confidence spam. In simple words, the destination recipient is not aware of a scenario in which the SPF result is Fail, and they are not aware of the fact that the E-mail message could be a spoofed E-mail. 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. To avoid this, you can create separate records for each subdomain. A7: Technically speaking, each recipient has access to the information that is stored in the E-mail message header and theoretically, we can see the information about the SPF = Fail result. For example, in an Exchange Online based environment, we can activate an Exchange Online server setting that will mark each E-mail message that didnt pass the SPF verification test (SPF = fail) as spam mail. 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. Microsoft believes that the risk of continuing to allow unauthenticated inbound email is higher than the risk of losing legitimate inbound email. Despite that the first association regarding the right response to an event in which the sender uses an E-mail address that includes our organization domain name + the result from the SPF sender verification test is fail, is to block and delete such E-mails; I strongly recommend not doing so. We don't recommend that you use this qualifier in your live deployment. Received-SPF: Fail (protection.outlook.com: domain of mydomain.com does not designate 67.220.184.98 as permitted sender) receiver=protection.outlook.com; why spffailed mails normally received? The SPF mechanism doesnt perform and concrete action by himself. I am using Cloudflare, if you dont know how to change or add DNS records, then contact your hosting provider. The E-mail is a legitimate E-mail message. 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. A2: The purpose of using the identity of one of our organization users is because, there is a high chance that the Innocent victim (our organization user), will tend to believe someone he knows vs. some sender that he doesnt know (and for this reason tends to trust less). If you have anti-spoofing enabled and the SPF record: hard fail ( MarkAsSpamSpfRecordHardFail) turned on, you will probably get more false positives. The Exchange rule includes three main parts: In our specific scenario, we will use the Exchange rule using the following configuration setting-, Phase 1. 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. In these examples, contoso.com is the sender and woodgrovebank.com is the receiver. 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. Typically, email servers are configured to deliver these messages anyway. Add SPF Record As Recommended By Microsoft. Enforcement rule is usually one of the following: Indicates hard fail. The three primary SPF sender verification test results could be: Regarding the result, in which the SPF result is Pass, this is a sign that we can be sure that the mail sender is a legitimate user, and we can trust this sender. Think of your scanners that send email to external contacts, (web)applications, newsletters systems, etc. In some cases, like the salesforce.com example, you have to use the domain in your SPF TXT record, but in other cases, the third-party may have already created a subdomain for you to use for this purpose. Best practices and the latest news on Microsoft FastTrack, The employee experience platform to help people thrive at work, Expand your Azure partner-to-partner network, Bringing IT Pros together through In-Person & Virtual events. For detailed information about other syntax options, see SPF TXT record syntax for Office 365. In addition to IP addresses, you can also configure your SPF TXT record to include domains as senders. If you are a small business, or are unfamiliar with IP addresses or DNS configuration, call your Internet domain registrar (ex. Nearly all large email services implement traditional SPF, DKIM, and DMARC checks. If you're using IPv6 IP addresses, replace ip4 with ip6 in the examples in this article. We reviewed the need for completing the missing part of our SPF implementation, in which we need to capture an event of SPF sender verification test in which the result is fail and, especially, in a scenario in which the sender E-mail address includes our domain name (most likely certainly a sign that this is a Spoof mail attack). The reason for the outcome of SPF = Fail is related to a missing configuration on the sending mail infrastructure., The E-mail address of the sender, uses the domain name of, The result from the SPF sender verification test is , The popular organization users who are being attacked, The various types of Spoofing or Phishing attacks, The E-mail address of the sender includes our domain name (in our specific scenario; the domain name is, The result of the SPF sender verification check is fail (SPF = Fail). Destination email systems verify that messages originate from authorized outbound email servers. 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 . Use the 90-day Defender for Office 365 trial at the Microsoft 365 Defender portal trials hub. Scenario 2 the sender uses an E-mail address that includes. Microsoft itself first adopted the new email authentication requirements several weeks before deploying it to customers. For example: Having trouble with your SPF TXT record? You can read a detailed explanation of how SPF works here. But it doesnt verify or list the complete record. This option enables us to activate an EOP filter, which will mark incoming E-mail message that has the value of "SFP =Fail" as spam mail (by setting a high SCL value). As you can see in the screenshot below, Microsoft has already detected an existing SPF record, marking it invalid.We can safely add include:spf.protection.outlook.com to our SPF record.In your DNS Hosting Provider, look up the SPF record, and click edit. Add include:spf.protection.outlook.com before the -all elementSo in this case it would be:v=spf1 ip4:213.14.15.20 include:servers.mcsv.net include:spf.protection.outlook.com -all. Yes. 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. Find out more about the Microsoft MVP Award Program. Best thing to do is report the message via the Junk add-in and open a support case to have it properly investigated. ip6 indicates that you're using IP version 6 addresses. Although SPF is designed to help prevent spoofing, but there are spoofing techniques that SPF can't protect against. Most of the time, I dont recommend executing a response such as block and delete E-mail that was classified as spoofing mail because the simple reason is that probably we will never have full certainty that the specific E-mail message is indeed spoofed mail. Q6: In case that the information in the E-mail message header includes results of SPF = Fail, does the destination recipient is aware of this fact? The following examples show how SPF works in different situations. The -all rule is recommended. Microsoft Office 365. 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. To defend against these, once you've set up SPF, you should configure DKIM and DMARC for Office 365. SPF (Sender Policy Framework) is an email authorization protocol that checks the sender's IP address against a list of IPs published on the domain used as the Return-Path header of the email sent. This applies to outbound mail sent from Microsoft 365. Another distinct advantage of using Exchange Online is the part which enables us to select a very specific response (action), that will suit our needs such as Perpend the E-mail message subject, Send warning E-mail, send the Spoof mail to quarantine, generate the incident report and so on. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. No. The condition part will activate the Exchange rule when the combination of the following two events will occur: In phase 1 (the learning mode), we will execute the following sequence of actions: This phase is implemented after we are familiar with the different scenarios of Spoof mail attacks. There is no right answer or a definite answer that will instruct us what to do in such scenarios. . Indicates neutral. In this article, I am going to explain how to create an Office 365 SPF record. Solution: Did you try turning SPF record: hard fail on, on the default SPAM filter? It is published as a Domain Name System (DNS) record for that domain in the form of a specially formatted TXT record. In this step, we want to protect our users from Spoof mail attack. 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). Oct 26th, 2018 at 10:51 AM. In reality, we can never be sure in 100%, that the E-mail message is indeed spoofed E-mail message or, a legitimate E-mail message. Continue at Step 7 if you already have an SPF record. Instruct the Exchange Online what to do regarding different SPF events.. A scenario in which hostile element spoofs the identity of a legitimate recipient, and tries to attack our organization users. 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. Legitimate newsletters might use web bugs, although many consider this an invasion of privacy. This scenario can have two main clarifications: A legitimate technical problem a scene in which we are familiar with the particular mail server/software component, that sent an email message on behalf of our domain, A non-legitimate mail element a scenario in which we discover that our organization uses mail server or mail applications that send an E-mail message on behalf of our domain, and we are now aware of these elements.. Use trusted ARC Senders for legitimate mailflows. This phase can describe as the active phase in which we define a specific reaction to such scenarios. Some bulk mail providers have set up subdomains to use for their customers. Conditional Sender ID filtering: hard fail. v=spf1 ip4:10.10.10.1/16 mx ptr:Sender.domain.com include:spf.protection.outlook.com ~all. Also, if you're using DMARC with p=quarantine or p=reject, then you can use ~all. Here is an example of an SPF record published on domain X, authorizing Office 365 to send emails on its behalf: For example, let's say that your custom domain contoso.com uses Office 365. Normally you use the -all element which indicates a hard fail. The SPF sender verification can mark a particular E-mail message with a value to SPF = none or SPF = Fail. To get started, see Use DKIM to validate outbound email sent from your custom domain in Microsoft 365. Below is an example of adding the office 365 SPF along with onprem in your public DNS server. This record probably looks like this: If you're a fully hosted customer, that is, you have no on-premises mail servers that send outbound mail, this is the only SPF TXT record that you need to publish for Office 365. For more information, see Example: SPF TXT record for multiple outbound on-premises mail servers and Microsoft 365. domain name is the domain you want to add as a legitimate sender. Some online tools will even count and display these lookups for you. However, if you bought Office 365 Germany, part of Microsoft Cloud Germany, you should use the include statement from line 4 instead of line 2. A good option could be, implementing the required policy in two phases-. Email advertisements often include this tag to solicit information from the recipient. Office 365 supports only one SPF record (a TXT record that defines SPF) for your domain. Not all phishing is spoofing, and not all spoofed messages will be missed. In reality, the recipient will rarely access data stored in the E-mail message header, and even if they access the data, they dont have the ability to understand most of the information thats contained within the E-mail header. DKIM is the second step in protecting your mail domain against spoofing and phishing attempts. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. For questions and answers about anti-malware protection, see Anti-malware protection FAQ. Make sure that you include all mail systems in your SPF record, otherwise, mail sent from these systems will be listed as spam messages. If you have a hybrid configuration (some mailboxes in the cloud, and some mailboxes on premises) or if you're an Exchange Online Protection standalone customer, add the outbound IP address of . DKIM email authentication's goal is to prove the contents of the mail haven't been tampered with. Disable SPF Check On Office 365. Phishing emails Fail SPF but Arrive in Inbox Posted by enyr0py 2019-04-23T19:01:42Z. Although there are other syntax options that are not mentioned here, these are the most commonly used options. The meaning of the SPF = Fail is that we cannot trust the mail server that sends the E-mail message on behalf of the sender and for this reason, we cannot trust the sender himself. Keep in mind, that SPF has a maximum of 10 DNS lookups. For tips on how to avoid this, see Troubleshooting: Best practices for SPF in Microsoft 365. It's a first step in setting up the full recommended email authentication methods of SPF, DKIM, and DMARC. A wildcard SPF record (*.) 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. Q3: What is the purpose of the SPF mechanism? office 365 mail SPF Fail but still delivered, Re: office 365 mail SPF Fail but still delivered. The meaning is a hostile element that executes spoofing or Phishing attacks and uses a sender E-mail address that includes our domain name. This is reserved for testing purposes and is rarely used. This improved reputation improves the deliverability of your legitimate mail. In all Microsoft 365 organizations, the Advanced Spam Filter (ASF) settings in anti-spam policies in EOP allow admins to mark messages as spam based on specific message properties. 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. The protection layers in EOP are designed work together and build on top of each other. 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. Given that the SPF record is configured correctly, and given that the SPF record includes information about all of our organizations mail server entities, there is no reason for a scenario in which a sender E-mail address which includes our domain name will mark by the SPF sender verification test as Fail. This list is known as the SPF record. More info about Internet Explorer and Microsoft Edge. For example, the company MailChimp has set up servers.mcsv.net. With a soft fail, this will get tagged as spam or suspicious. 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. 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.. To work around this problem, use SPF with other email authentication methods such as DKIM and DMARC. In reality, there is always a chance that the E-mail message in which the sender uses our domain name includes and the result from the SPF sender verification test is Fail could be related to some miss configuration issue. This change should reduce the risk of SharePoint Online notification messages ending up in the Junk Email folder. You will also need to watch out for the condition where you SPF record contains more than 10 DNS lookups, and take action to fix it when it happens. Notify me of followup comments via e-mail. The 6 commonly used elements in an SPF record are: You can add as many include: or ip4: elements to your SPF record as you need. SPF sender verification check fail | our organization sender identity. An SPF record is a DNS entry containing the IP addresses of an organization's official email servers and domains that can send emails on behalf of your business. i check headers and see that spf failed. 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. LazyAdmin.nl also participates in affiliate programs with Microsoft, Flexoffers, CJ, and other sites. This ASF setting is no longer required. Messages that contain hyperlinks that redirect to TCP ports other than 80 (HTTP), 8080 (alternate HTTP), or 443 (HTTPS) are marked as spam. In this category, we can put every event in which a legitimate E-mail message includes the value of SPF = Fail. 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. We cannot be sure if the mail infrastructure of the other side support SPF, and if he implements an SPF sender verification test. If you go over that limit with your include, a-records an more, mxtoolbox will show up an error! 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. Test: ASF adds the corresponding X-header field to the message. ASF specifically targets these properties because they're commonly found in spam. If a message exceeds the 10 limit, the message fails SPF. What does SPF email authentication actually do? The rest of this article uses the term SPF TXT record for clarity. After a specific period, which we allocate for examining the information that collected, we can move on to the active phase, in which we execute a specific action in a scenario that the Exchange rule identifies an E-mail message that is probably Spoof mail. What are the possible options for the SPF test results? Outlook.com might then mark the message as spam. When it finds an SPF record, it scans the list of authorized addresses for the record. You can also subscribe without commenting. Indicates soft fail. You can only have one SPF TXT record for a domain. Given that we are familiar with the exact structure of our mail infrastructure, and given that we are sure that our SPF record includes the right information about our mail servers IP address, the conclusion is that there is a high chance that the E-mail is indeed spoofed E-mail! 04:08 AM In this scenario, we can choose from a variety of possible reactions.. This defines the TXT record as an SPF TXT record. Login at admin.microsoft.com Navigate to your domain - Expand Settings and select Domains - Select your custom Domain (not the <companyname>.onmicrosoft.com domain Lookup the SPF Record Click on the DNS Records tab. If it finds another include statement within the records for contoso.net or contoso.org, it will follow those too. This option combines an SPF check with a Sender ID check to help protect against message headers that contain forged senders. 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. As mentioned, in an Exchange-based environment, we can use the Exchange rule as a tool that will help us to capture the event of SPF = Fail and also, choose the required response to such an event. Test mode is not available for the following ASF settings: Microsoft 365 organizations with Exchange Online mailboxes. 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). 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. 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. 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. Per Microsoft. Generate and Send an incident report to a designated recipient (shared mailbox) that will include information about the characters of the event + the original E-mail message. adkim . Unfortunately, no. Off: The ASF setting is disabled. A9: The answer depends on the particular mail server or the mail security gateway that you are using. In case that your organization experiences a scenario in which your mail server IP address, In the current article and the next article: My E-mail appears as spam | Troubleshooting, In the current article, we will review how to deal with Spoof mail by creating, Your email address will not be published. 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. The presence of filtered messages in quarantine. 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.