You can use nslookup to view your DNS records, including your SPF TXT record. This is no longer required. Why SPF Authentication Fails: none, neutral, fail (hard fail), soft A soft fail would look like this: v=spf1 ip4 192.xx.xx.xx ~all SPF identifies which mail servers are allowed to send mail on your behalf. Also, if you're using DMARC with p=quarantine or p=reject, then you can use ~all. 0 Likes Reply Q10: Why our mail server doesnt automatically block incoming E-mail that has the value of SPF = Fail? The SPF information identifies authorized outbound email servers. 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. This improved reputation improves the deliverability of your legitimate mail. 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. Fix Your SPF Errors Now SPF Check Path The path for the check is as follows Exchange Admin Center > Protection > Spam Filter > Double Click Default > Advanced Options > Set SPF record: Hard fail: Off One of the prime reasons why Office 365 produces a validation error is an invalid SPF record. Q3: What is the purpose of the SPF mechanism? Nearly all large email services implement traditional SPF, DKIM, and DMARC checks. An SPF record is a list of authorized sending hosts for the domain listed in the return path of an email. Need help with adding the SPF TXT record? ASF specifically targets these properties because they're commonly found in spam. There is no right answer or a definite answer that will instruct us what to do in such scenarios. 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. ASF specifically targets these properties because they're commonly found in spam. 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. 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. Unfortunately, no. You can't report messages that are filtered by ASF as false positives. 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. Use trusted ARC Senders for legitimate mailflows. Do nothing, that is, don't mark the message envelope. You can read a detailed explanation of how SPF works here. As mentioned, the SPF sender verification test just stamp the E-mail message with information about the SPF test result. The second one reads the "Authentication-Results" line in the header information and if it says "Fail" sends the email to quarantine. Its a good idea to configure DKIM after you have configured SPF. One drawback of SPF is that it doesn't work when an email has been forwarded. Edit Default > advanced optioins > Mark as Spam > SPF record: hard fail: Off. This option combines an SPF check with a Sender ID check to help protect against message headers that contain forged senders. SPF fail, also known as SPF hardfail, is an explicit statement that the client is not authorized to use the domain in the given identity. Otherwise, use -all. Use the syntax information in this article to form the SPF TXT record for your custom domain. 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. 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 identifies which mail servers are allowed to send mail on your behalf. 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. 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). This ASF setting is no longer required. ASF settings in EOP - Office 365 | Microsoft Learn Read Troubleshooting: Best practices for SPF in Office 365. I always try to make my reviews, articles and how-to's, unbiased, complete and based on my own expierence. Disabling the protection will allow more phishing and spam messages to be delivered in your organization. The event in which the SPF sender verification test result is Fail, can be realized in two main scenarios. Go to your messaging server(s) and find out the External IP addresses (needed from all on-premises messaging servers). Use the 90-day Defender for Office 365 trial at the Microsoft 365 Defender portal trials hub. The answer is that as always; we need to avoid being too cautious vs. being too permissive. By analyzing the information thats collected, we can achieve the following objectives: 1. See You don't know all sources for your email. The enforcement rule is usually one of these options: Hard fail. All SPF TXT records end with this value. 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. 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. For questions and answers about anti-spam protection, see Anti-spam protection FAQ. Its Free. Find out more about the Microsoft MVP Award Program. 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. 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). In order to protect against these, once you have set up SPF, you should also configure DKIM and DMARC for Microsoft 365. Implement the SPF Fail policy using a two-phase procedure the learning/inspection phase and the production phase. If you provided a sample message header, we might be able to tell you more. It can take a couple of minutes up to 24 hours before the change is applied. A scenario in which hostile element spoofs the identity of a legitimate recipient, and tries to attack our organization users. Indicates soft fail. You can only create one SPF TXT record for your custom domain. Notify me of followup comments via e-mail. Office 365 supports only one SPF record (a TXT record that defines SPF) for your domain. A wildcard SPF record (*.) Email Authentication 101 [The Outlook for 2023] Off: The ASF setting is disabled. and/or whitelist Messagelab (as it will not be listed as permitted sender for the domain you are checking): Office 365 Admin > Exchange admin center > protection > connection filter. [SOLVED] Office 365 Prevent Spoofing - The Spiceworks Community 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). This article describes how you form your SPF TXT record and provides best practices for working with the services in Microsoft 365. 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 . Set up SPF to help prevent spoofing - Office 365 | Microsoft Learn By looking at your SPF TXT record and following the chain of include statements and redirects, you can determine how many DNS lookups the record requires. 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. You then define a different SPF TXT record for the subdomain that includes the bulk email. The Exchange rule includes three main parts: In our specific scenario, we will use the Exchange rule using the following configuration setting-, Phase 1. For example, exacttarget.com has created a subdomain that you need to use for your SPF TXT record: When you include third-party domains in your SPF TXT record, you need to confirm with the third-party which domain or subdomain to use in order to avoid running into the 10 lookup limit. How to Set Up DMARC, DKIM, and SPF in Office 365 (O365) Exchange Server Learn about who can sign up and trial terms here. Your support helps running this website and I genuinely appreciate it. Figure out what enforcement rule you want to use for your SPF TXT record. - last edited on This tool checks your complete SPF record is valid. We recommend that you disable this feature as it provides almost no additional benefit for detecting spam or phishing message, and would instead generate mostly false positives. The SPF mechanism is not responsible for notifying us or, to draw our attention to events in which the result from the SPF sender verification test considered as Fail.. 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"). In order to help prevent denial of service attacks, the maximum number of DNS lookups for a single email message is 10. 01:13 AM Depending on the property, ASF detections will either mark the message as Spam or High confidence spam. Did you know you can try the features in Microsoft 365 Defender for Office 365 Plan 2 for free? 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. This tag allows plug-ins or applications to run in an HTML window. 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.. 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. Not every email that matches the following settings will be marked as spam. Based on your mentioned description about "SPF authentication fails for our outbound emails sent by Exchange Online despite having this DNS record : v=spf1 include:spf.protection.outlook.com -all", once could you please provide us your detailed error message screenshot, your SPF record and domain via private message? Scenario 1. 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. In the following section, I like to review the three major values that we get from the SPF sender verification test. DKIM is the second step in protecting your mail domain against spoofing and phishing attempts. Solution: Did you try turning SPF record: hard fail on, on the default SPAM filter? However, your risk will be higher. If it finds another include statement within the records for contoso.net or contoso.org, it will follow those too. 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). Set Up SPF Record Office 365 to Prevent Spoofing and - DuoCircle 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. In scenario 1, in which the sender uses the identity of a well-known organization, we can never be sure definitively that the E-mail message is indeed a spoofed E-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. 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. As mentioned, in this phase our primary purpose is to capture Spoof mail attack events (SPF = Fail) and create a log which will be used for analyzing the information thats gathered. SPF issue in Office365 with spoofing : r/Office365 - reddit The meaning of SPF =none is that a particular organization that is using a specific domain name doesnt support SPF or in other words, doesnt enable us to verify the identity of the sender that their E-mail message includes the specific domain name. adkim . 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. Failed SPF authentication for Exchange Online - Microsoft Community 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 . 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. Each SPF TXT record contains three parts: the declaration that it's an SPF TXT record, the IP addresses that are allowed to send mail from your domain and the external domains that can send on your domain's behalf, and an enforcement rule. 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. 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. In addition to IP addresses, you can also configure your SPF TXT record to include domains as senders. 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. Add a predefined warning message, to the E-mail message subject. The Exchange tool/option that we use for the purpose of gathering information about a particular mail flow event is described as an incident report. To fix this issue, a sender rewriting scheme is being rolled out in Office 365 that will change the sender email address to use the domain of the tenant whose mailbox is forwarding the message. ip4 indicates that you're using IP version 4 addresses. 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. Destination email systems verify that messages originate from authorized outbound email servers. 04:08 AM Microsoft suggests that the SPF of Spambrella gets added to the domain's SPF. 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. If an SPF TXT record exists, instead of adding a new record, you need to update the existing 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. What is SPF? Customers on US DC (US1, US2, US3, US4 . 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. Some online tools will even count and display these lookups for you. The first one reads the "Received-SPF" line in the header information and if it says "SPF=Fail" it sends the message to quarantine. Q2: Why does the hostile element use our organizational identity? Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. What is the conclusion such as scenario, and should we react to such E-mail message? These are added to the SPF TXT record as "include" statements. Attackers will adapt to use other techniques (for example, compromised accounts or accounts in free email services). For example: Having trouble with your SPF TXT record? The element that should read this information (the SPF sender verification test result),and do something about it, is the mail server or the mail security gateway that represents the organization mail infrastructure. 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. This allows you to copy the TXT value and also check if your domain already has an SPF record (it will be listed as Invalid Entry). GoDaddy, Bluehost, web.com) & ask for help with DNS configuration of SPF (and any other email authentication method). In each of these scenarios, if the SPF sender verification test value is Fail the E-mail will mark as spam. Once you've formed your record, you need to update the record at your domain registrar. Also, the original destination recipient will get an E-mail notification, which informs him that a specific E-mail message that was sent to him was identified as Spoof mail and for this reason didnt automatically send to his mailbox. If you are a small business, or are unfamiliar with IP addresses or DNS configuration, call your Internet domain registrar (ex. Instead, ensure that you use TXT records in DNS to publish your SPF information. 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. The rest of this article uses the term SPF TXT record for clarity. 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. Include the following domain name: spf.protection.outlook.com. To work around this problem, use SPF with other email authentication methods such as DKIM and DMARC. SPF is designed to help prevent spoofing, but there are spoofing techniques that SPF can't protect against. We . Here is an example of an SPF record published on domain X, authorizing Office 365 to send emails on its behalf: Hope this helps. All SPF TXT records start with this value, Office 365 Germany, Microsoft Cloud Germany only, On-premises email system.