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. The E-mail address of the sender uses the domain name of a well-known bank. For tips on how to avoid this, see Troubleshooting: Best practices for SPF in Microsoft 365. is required for every domain and subdomain to prevent attackers from sending email claiming to be from non-existent subdomains. Your email address will not be published. (e.g., domain alignment for SPF); d - send only if DKIM fails; s - send only when SPF fails. To be able to avoid from a false-positive event, meaning an event in which a legitimate E-mail message mistakenly identified as Spoof mail, I prefer more refinement actions such as send the E-mail to approval, send the E-mail to quarantine and so on. 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. What is SPF? 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. Usually, this is the IP address of the outbound mail server for your organization. The protection layers in EOP are designed work together and build on top of each other. You then define a different SPF TXT record for the subdomain that includes the bulk email. You can only create one SPF TXT record for your custom domain. TechCommunityAPIAdmin. Destination email systems verify that messages originate from authorized outbound email servers. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. Messages with no subject, no content in the message body, and no attachments are marked as high confidence spam. office 365 mail SPF Fail but still delivered, Re: office 365 mail SPF Fail but still delivered. This setting combines an SPF check with a Sender ID check to help protect against message headers that contain forged senders. This ASF setting is no longer required. 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. We recommend the value -all. Test: ASF adds the corresponding X-header field to the message. For advanced examples and a more detailed discussion about supported SPF syntax, see How SPF works to prevent spoofing and phishing in Office 365. IP address is the IP address that you want to add to the SPF TXT record. SPF record types were deprecated by the Internet Engineering Task Force (IETF) in 2014. Messages that hard fail a conditional Sender ID check are marked as spam. 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. LazyAdmin.nl also participates in affiliate programs with Microsoft, Flexoffers, CJ, and other sites. In each of these scenarios, if the SPF sender verification test value is Fail the E-mail will mark as spam. 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 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). And as usual, the answer is not as straightforward as we think. The defense action that we will choose to implement in our particular scenario is a process in which E-mail message that identified as Spoof mail, will not be sent to the original destination recipient.. For example, suppose the user at woodgrovebank.com has set up a forwarding rule to send all email to an outlook.com account: The message originally passes the SPF check at woodgrovebank.com but it fails the SPF check at outlook.com because IP #25 isn't in contoso.com's SPF TXT record. 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. 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. In the current article, I want to provide you with a useful way, to implement a mail security policy related to an event in which the result of the SPF sender verification check is Fail. If we want to be more precise, an event in which the SPF sender verification test result is Fail, and the sender used the E-mail address, which includes our domain name. office 365 mail SPF Fail but still delivered Hello today i received mail from my organization. Sender Policy Framework or SPF decides if a sender is authorized to send emails for any domain. Sender Policy Framework, or SPF, is an email authentication technique that helps protect email senders and recipients from spam, phishing and spoofing. We . 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. After examining the information collected, and implementing the required adjustment, we can move on to the next phase. In each of the above scenarios, the event in which the SPF sender verification test ended with SPF = Fail result is not good. Scenario 1. For instructions, see Gather the information you need to create Office 365 DNS records. Solved Microsoft Office 365 Email Anti-Spam. 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 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. 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. 0 Likes Reply 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. For more information, see Configure anti-spam policies in EOP. 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. SPF sender verification test fail | External sender identity. by This is implemented by appending a -all mechanism to an SPF record. This is the main reason for me writing the current article series. 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. 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. ASF specifically targets these properties because they're commonly found in spam. For a list of domain names you should include for Microsoft 365, see External DNS records required for SPF. Although there are other syntax options that are not mentioned here, these are the most commonly used options. 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. What is the conclusion such as scenario, and should we react to such E-mail message? In this scenario, our mail server accepts a request to deliver an email message to one of our organization recipients. 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. For questions and answers about anti-malware protection, see Anti-malware protection FAQ. Q10: Why our mail server doesnt automatically block incoming E-mail that has the value of SPF = Fail? Some online tools will even count and display these lookups for you. 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). SPF records: Hard Fail vs Soft Fail? - cPanel Include the following domain name: spf.protection.outlook.com. Messages sent from Microsoft 365 to a recipient within Microsoft 365 will always pass SPF. 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. If you have a hybrid deployment (that is, you have some mailboxes on-premises and some hosted in Microsoft 365), or if you're an Exchange Online Protection (EOP) standalone customer (that is, your organization uses EOP to protect your on-premises mailboxes), you should add the outbound IP address for each of your on-premises edge mail servers to the SPF TXT record in DNS. By rewriting the SMTP MAIL FROM, SRS can ensure that the forwarded message passes SPF at the next destination. The SPF sender verification can mark a particular E-mail message with a value to SPF = none or SPF = Fail. ASF specifically targets these properties because they're commonly found in spam. 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. Some services have other, more strict checks, but few go as far as EOP to block unauthenticated email and treat them as spoofed messages. Edit Default > advanced optioins > Mark as Spam > SPF record: hard fail: Off. The E-mail message is a spoofed E-mail message that poses a risk of attacking our organization users. You can also specify IP address ranges using CIDR notation, for example ip4:192.168.0.1/26. SPF = Fail but still delivered to inbox - Microsoft Community Hub The Exchange rule includes three main parts: In our specific scenario, we will use the Exchange rule using the following configuration setting-, Phase 1. Even when we get to the production phase, its recommended to choose a less aggressive response. Best thing to do is report the message via the Junk add-in and open a support case to have it properly investigated. Once you have formed your SPF TXT record, you need to update the record in DNS. 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. 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. 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. Disable SPF Check On Office 365. When Microsoft enabled this feature in 2018, some false positives happened (good messages were marked as bad). It doesn't have the support of Microsoft Outlook and Office 365, though. If an SPF TXT record exists, instead of adding a new record, you need to update the existing record. Q5: Where is the information about the result from the SPF sender verification test stored? SPF Record Error when sending to one domain in particular Although SPF is designed to help prevent spoofing, but there are spoofing techniques that SPF can't protect against. is the domain of the third-party email system. 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? 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. Default value - '0'. While there was disruption at first, it gradually declined. A soft fail would look like this: v=spf1 ip4 192.xx.xx.xx ~all ip4 indicates that you're using IP version 4 addresses. Periodic quarantine notifications from spam and high confidence spam filter verdicts. Messages that contain words from the sensitive word list in the subject or message body are marked as high confidence spam. To do this, change include:spf.protection.outlook.com to include:spf.protection.outlook.de. More info about Internet Explorer and Microsoft Edge. This defines the TXT record as an SPF TXT record. The E-mail is a legitimate E-mail message. 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. 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. This will avoid the rejections taking place by some email servers with strict settings for their SPF checks. In this category, we can put every event in which a legitimate E-mail message includes the value of SPF = Fail. Instead, ensure that you use TXT records in DNS to publish your SPF information. Select 'This page' under 'Feedback' if you have feedback on this documentation. As mentioned, the SPF sender verification test just stamp the E-mail message with information about the SPF test result. The first one reads the "Received-SPF" line in the header information and if it says "SPF=Fail" it sends the message to quarantine. 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. These are added to the SPF TXT record as "include" statements. Messages that contain web bugs are marked as high confidence spam. 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. A scenario in which hostile element spoofs the identity of a legitimate recipient, and tries to attack our organization users. This article was written by our team of experienced IT architects, consultants, and engineers. If you have a hybrid environment with Office 365 and Exchange on-premises. Continue at Step 7 if you already have an SPF record. Unfortunately, no. 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. If you go over that limit with your include, a-records an more, mxtoolbox will show up an error! Anti-spoofing protection considers both SPF hard fails and a much wider set of criteria. Did you know you can try the features in Microsoft 365 Defender for Office 365 Plan 2 for free? 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. Customers on US DC (US1, US2, US3, US4 . If an email message causes more than 10 DNS lookups before it's delivered, the receiving mail server will respond with a permanent error, also called a permerror, and cause the message to fail the SPF check. Sharing best practices for building any app with .NET. 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. Why is SPF Check Failing with Office 365 - Spambrella 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. 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. 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. All SPF TXT records end with this value. 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. This is no longer required. LazyAdmin.nl is compensated for referring traffic and business to these companies at no expense to you. 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. 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. When it finds an SPF record, it scans the list of authorized addresses for the record. Learn about who can sign up and trial terms here. The responsibility of what to do in a particular SPF scenario is our responsibility! 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. Implementing SPF Fail policy using Exchange Online rule (dealing with A wildcard SPF record (*.) More info about Internet Explorer and Microsoft Edge, Microsoft Defender for Office 365 plan 1 and plan 2, You don't know all sources for your email, Advanced Spam Filter (ASF) settings in EOP. 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. Your support helps running this website and I genuinely appreciate it. The Microsoft 365 Admin Center only verifies if include:spf.protection.outlook.com is included in the SPF record. In many scenarios, the spoofed E-mail message will not be blocked even if the SPF value marked as Fail because of the tendency to avoid a possible event of false positives. This conception is half true. 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. Email advertisements often include this tag to solicit information from the recipient. 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. You can use nslookup to view your DNS records, including your SPF TXT record. @tsulafirstly, this mostly depends on the spam filtering policy you have configured. An SPF record is used to identify which mail servers (or systems) are allowed to send mail on your behalf. You can't report messages that are filtered by ASF as false positives. When you want to use your own domain name in Office 365 you will need to create an SPF record. Outlook.com might then mark the message as spam. Read Troubleshooting: Best practices for SPF in Office 365. This applies to outbound mail sent from Microsoft 365. SRS only partially fixes the problem of forwarded email. i check headers and see that spf failed. 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. Indicates neutral. This is used when testing SPF. You will need to create an SPF record for each domain or subdomain that you want to send mail from. office 365 mail SPF Fail but still delivered - Microsoft Community Hub 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). 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. The SPF information identifies authorized outbound email servers. This option combines an SPF check with a Sender ID check to help protect against message headers that contain forged senders.