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. 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.. 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). Include the following domain name: spf.protection.outlook.com. A soft fail would look like this: v=spf1 ip4 192.xx.xx.xx ~all Periodic quarantine notifications from spam and high confidence spam filter verdicts. Microsoft suggests that the SPF of Spambrella gets added to the domain's SPF. The protection layers in EOP are designed work together and build on top of each other. 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. Q10: Why our mail server doesnt automatically block incoming E-mail that has the value of SPF = Fail? Legitimate newsletters might use web bugs, although many consider this an invasion of privacy. and are the IP address and domain of the other email system that sends mail on behalf of your domain. 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. 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 . If an SPF TXT record exists, instead of adding a new record, you need to update the existing record. 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. A9: The answer depends on the particular mail server or the mail security gateway that you are using. Messages that use JavaScript or Visual Basic Script Edition in HTML are marked as high confidence spam. 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. One option that is relevant for our subject is the option named SPF record: hard fail. Messages sent from Microsoft 365 to a recipient within Microsoft 365 will always pass SPF. EOP includes a default spam filter policy, which includes various options that enable us to harden the existing mail security policy. Links to instructions on working with your domain registrar to publish your record to DNS are also provided. To work around this problem, use SPF with other email authentication methods such as DKIM and DMARC. This tool checks your complete SPF record is valid. 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. IT, Office365, Smart Home, PowerShell and Blogging Tips. - last edited on 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. Step 2: Set up SPF for your domain. The receiving server may also respond with a non-delivery report (NDR) that contains an error similar to these: Some SPF TXT records for third-party domains direct the receiving server to perform a large number of DNS lookups. 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. You can read a detailed explanation of how SPF works here. This ASF setting is no longer required. This is the default value, and we recommend that you don't change it. This type of scenario, there is a high chance that we are experiencing a Spoof mail attack! 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. If you know all of the authorized IP addresses for your domain, list them in the SPF TXT record, and use the -all (hard fail) qualifier. 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). Implement the SPF Fail policy using a two-phase procedure the learning/inspection phase and the production phase. @tsulafirstly, this mostly depends on the spam filtering policy you have configured. See You don't know all sources for your email. 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? However, anti-phishing protection works much better to detect these other types of phishing methods. 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. 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. 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. 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. However, over time, senders adjusted to the requirements. This is no longer required. 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. 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. The presence of filtered messages in quarantine. On-premises email organizations where you route. Microsoft maintains a dynamic but non-editable list of words that are associated with potentially offensive messages. For example: Having trouble with your SPF TXT record? First, we are going to check the expected SPF record in the Microsoft 365 Admin center. We don't recommend that you use this qualifier in your live deployment. Enforcement rule is usually one of the following: Indicates hard fail. 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. This is reserved for testing purposes and is rarely used. Messages with no subject, no content in the message body, and no attachments are marked as high confidence spam. The second one reads the "Authentication-Results" line in the header information and if it says "Fail" sends the email to quarantine. The Exchange rule includes three main parts: In our specific scenario, we will use the Exchange rule using the following configuration setting-, Phase 1. This is the scenario in which we get a clear answer regarding the result from the SPF sender verification test the SPF test fail! Once you've formed your record, you need to update the record at your domain registrar. Scenario 1 the sender uses an E-mail address that includes a domain name of a well-known organization. This is implemented by appending a -all mechanism to an SPF record. 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. DKIM email authentication's goal is to prove the contents of the mail haven't been tampered with. If you set up mail when you set up Microsoft 365, you already created an SPF TXT record that identifies the Microsoft messaging servers as a legitimate source of mail for your domain. This change should reduce the risk of SharePoint Online notification messages ending up in the Junk Email folder. 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. Soft fail. For detailed information about other syntax options, see SPF TXT record syntax for Office 365. 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. In addition to IP addresses, you can also configure your SPF TXT record to include domains as senders. And as usual, the answer is not as straightforward as we think. For example, vs. the Exchange Online spam filter policy that marks every incoming E-mail message that has the value of SPF = Fail as spam mail without distinction, when using the option of Exchange rule, we can define a more refined version of this scenario, a condition in which only if the sender uses our domain name + the result from the SPF verification test is Fail, only, then the E-mail message will be identified as Spoof mail. 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. by Solution: Did you try turning SPF record: hard fail on, on the default SPAM filter? But it doesnt verify or list the complete record. 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. 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. 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? In order to use a custom domain, Office 365 requires that you add a Sender Policy Framework (SPF) TXT record to your DNS record to help prevent spoofing. These are added to the SPF TXT record as "include" statements. Next, see Use DMARC to validate email in Microsoft 365. In our scenario, the organization domain name is o365info.com. When the receiving messaging server gets a message from joe@contoso.com, the server looks up the SPF TXT record for contoso.com and finds out whether the message is valid. Learn about who can sign up and trial terms here. Gather this information: The SPF TXT record for your custom domain, if one exists. A8: The responsibility of the SPF mechanism is to stamp the E-mail message with the SPF sender verification test results. In each of the above scenarios, the event in which the SPF sender verification test ended with SPF = Fail result is not good. Include the following domain name: spf.protection.outlook.com. This type of mail threat appears in two flavors: In this section, I would like to review a couple of popular misconceptions that relate to the SPF standard. 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. Your email address will not be published. If you have a hybrid configuration (some mailboxes in the cloud, and . For questions and answers about anti-malware protection, see Anti-malware protection FAQ. 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. Anti-spoofing protection considers both SPF hard fails and a much wider set of criteria. Typically, email servers are configured to deliver these messages anyway. Need help with adding the SPF TXT record? We recommend the value -all. The setting is located at Exchange admin Center > protection > spam filter > double click Default > advanced options > set SPF record: hard fail: off. 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. Identify a possible miss configuration of our mail infrastructure. Edit Default > advanced optioins > Mark as Spam > SPF record: hard fail: Off. You do not need to make any changes immediately, but if you receive the "too many lookups" error, modify your SPF TXT record as described in Set up SPF in Microsoft 365 to help prevent spoofing. Microsoft believes that the risk of continuing to allow unauthenticated inbound email is higher than the risk of losing legitimate inbound email. A good option could be, implementing the required policy in two phases-. A1: A Spoof mail attack implemented when a hostile element, uses a seemingly legitimate sender identity. 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. Text. 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. Indicates neutral. In these examples, contoso.com is the sender and woodgrovebank.com is the receiver. If you have a hybrid environment with Office 365 and Exchange on-premises. Messages that hard fail a conditional Sender ID check are marked as 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. While there was disruption at first, it gradually declined. SPF identifies which mail servers are allowed to send mail on your behalf. LazyAdmin.nl is compensated for referring traffic and business to these companies at no expense to you. The number of messages that were misidentified as spoofed became negligible for most email paths. Office 365 supports only one SPF record (a TXT record that defines SPF) for your domain. In case we want to get more information about the event or in case we need to deliver the E-mail message to the destination recipient, we will have the option. In the following section, I like to review the three major values that we get from the SPF sender verification test. This improved reputation improves the deliverability of your legitimate mail. For questions and answers about anti-spam protection, see Anti-spam protection FAQ. The rest of this article uses the term SPF TXT record for clarity. The event in which the SPF sender verification test result is Fail, can be realized in two main scenarios. You will need to create an SPF record for each domain or subdomain that you want to send mail from. This phase can describe as the active phase in which we define a specific reaction to such scenarios. 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. Previously, you had to add a different SPF TXT record to your custom domain if you also used SharePoint Online. Creating multiple records causes a round robin situation and SPF will 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"). Can we say that we should automatically block E-mail message which their organization doesnt support the use of SPF? When this mechanism is evaluated, any IP address will cause SPF to return a fail result. Indicates soft fail. 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. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. Include the following domain name: spf.protection.outlook.com. Join the movement and receive our weekly Tech related newsletter. These tags are used in email messages to format the page for displaying text or graphics. Basically, SPF, along with DKIM, DMARC, and other technologies supported by Office 365, help prevent spoofing and phishing. In this scenario, we can choose from a variety of possible reactions.. i check headers and see that spf failed. A wildcard SPF record (*.) It can take a couple of minutes up to 24 hours before the change is applied. adkim . We recommend that you use always this qualifier. For example: Previously, you had to add a different SPF TXT record to your custom domain if you were using SharePoint Online. Use trusted ARC Senders for legitimate mailflows. Although SPF is designed to help prevent spoofing, but there are spoofing techniques that SPF can't protect against. 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. v=spf1 ip4:10.10.10.1/16 mx ptr:Sender.domain.com include:spf.protection.outlook.com ~all. 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? I hate spam to, so you can unsubscribe at any time. SPF validates the origin of email messages by verifying the IP address of the sender against the alleged owner of the sending domain. The SPF mechanism doesnt perform and concrete action by himself. For example, the company MailChimp has set up servers.mcsv.net. Here is an example of an SPF record published on domain X, authorizing Office 365 to send emails on its behalf: To defend against these, once you've set up SPF, you should configure DKIM and DMARC for Office 365. A great toolbox to verify DNS-related records is MXToolbox. If you have anti-spoofing enabled and the SPF record: hard fail ( MarkAsSpamSpfRecordHardFail) turned on, you will probably get more false positives. 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). If you provided a sample message header, we might be able to tell you more. What is the conclusion such as scenario, and should we react to such E-mail message? Also, if you're using DMARC with p=quarantine or p=reject, then you can use ~all. Edit Default > connection filtering > IP Allow list. I am using Cloudflare, if you dont know how to change or add DNS records, then contact your hosting provider. Test: ASF adds the corresponding X-header field to the message. 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). However, your risk will be higher. SRS only partially fixes the problem of forwarded email. 2. 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. DKIM is the second step in protecting your mail domain against spoofing and phishing attempts. Add a predefined warning message, to the E-mail message subject. 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. My opinion that blocking or rejecting such E-mail messages is too risky because, we cannot enforce other organizations to use SPF, although using SPF is recommended and help to protect the identity and the reputation of a particular domain. 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. Outlook.com might then mark the message as spam. 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. Update your SPF TXT record if you are hitting the 10 lookup limit and receiving errors that say things like, "exceeded the lookup limit" and "too many hops". i check headers and see that spf failed. 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. 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). However, there is a significant difference between this scenario. 0 Likes Reply Best thing to do is report the message via the Junk add-in and open a support case to have it properly investigated. GoDaddy, Bluehost, web.com) & ask for help with DNS configuration of SPF (and any other email authentication method). Received-SPF: Fail (protection.outlook.com: domain of mydomain.com does notdesignate 67.220.184.98 as permitted sender) receiver=protection.outlook.com; i check SPF at mxtoolbox and SPF is correctly configured. You can also subscribe without commenting. If you're the sender's email admin, make sure the SPF records for your domain at your domain registrar are set up correctly. 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. 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. For example, let's say that your custom domain contoso.com uses Office 365. You can only have one SPF TXT record for a domain. To get started, see Use DKIM to validate outbound email sent from your custom domain in Microsoft 365. 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. Go to your messaging server(s) and find out the External IP addresses (needed from all on-premises messaging servers). You need some information to make the record. See Report messages and files to Microsoft. Also, if you're only using SPF, that is, you aren't using DMARC or DKIM, you should use the -all qualifier. This conception is half true. Sharing best practices for building any app with .NET. 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. This option combines an SPF check with a Sender ID check to help protect against message headers that contain forged senders. Otherwise, use -all. The most important purpose of the learning/inspection mode phase is to help us to locate cracks and grooves in our mail infrastructure. (e.g., domain alignment for SPF); d - send only if DKIM fails; s - send only when SPF fails. An SPF record is used to identify which mail servers (or systems) are allowed to send mail on your behalf. Depending on the property, ASF detections will either mark the message as Spam or High confidence spam. I always try to make my reviews, articles and how-to's, unbiased, complete and based on my own expierence. More info about Internet Explorer and Microsoft Edge. 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. Did you know you can try the features in Microsoft 365 Defender for Office 365 Plan 2 for free? Disable SPF Check On Office 365. 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. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. Off: The ASF setting is disabled. 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. 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. 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. Jun 26 2020 ip6 indicates that you're using IP version 6 addresses. SPF determines whether or not a sender is permitted to send on behalf of a domain. Its a good idea to configure DKIM after you have configured SPF. 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. Normally you use the -all element which indicates a hard fail. In this scenario, our mail server accepts a request to deliver an email message to one of our organization recipients. In other words, using SPF can improve our E-mail reputation. 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. Sender Policy Framework or SPF decides if a sender is authorized to send emails for any domain. This article was written by our team of experienced IT architects, consultants, and engineers. Q5: Where is the information about the result from the SPF sender verification test stored? You need all three in a valid SPF TXT record. Gather the information you need to create Office 365 DNS records, Troubleshooting: Best practices for SPF in Office 365, How SPF works to prevent spoofing and phishing in Office 365, Common. To be able to get a clearer view of the different SPF = Fail scenarios, lets review the two types of SPF = Fail events. 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! SPF sender verification check fail | our organization sender identity. For example, create one record for contoso.com and another record for bulkmail.contoso.com. Scenario 1. Do nothing, that is, don't mark the message envelope. However, there are some cases where you may need to update your SPF TXT record in DNS. SPF is the first line of defense in this and is required by Microsoft when you want to use a custom domain instead of the onmicrosoft.com domain. With a soft fail, this will get tagged as spam or suspicious. Usually, this is the IP address of the outbound mail server for your organization. For information about the domains you'll need to include for Microsoft 365, see External DNS records required for SPF. All SPF TXT records end with this value. Q3: What is the purpose of the SPF mechanism? One drawback of SPF is that it doesn't work when an email has been forwarded.