For advanced examples, a more detailed discussion about supported SPF syntax, spoofing, troubleshooting, and how Office 365 supports SPF, see How SPF works to prevent spoofing and phishing in Office 365. 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. A scenario in which hostile element spoofs the identity of a legitimate recipient, and tries to attack our organization users. These are added to the SPF TXT record as "include" statements. 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. 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. To be able to use the SPF option we will need to implement by ourselves the following proceeds: Add to the DNS server that hosts our domain name the required SPF record, and verifies that the syntax of the SPF record is correct + verify that the SPF record includes information about all the entities that send an E-mail message on behalf of our domain name. Yes. 04:08 AM 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. Notify me of followup comments via e-mail. What are the possible options for the SPF test results? ip6 indicates that you're using IP version 6 addresses. 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. Add SPF Record As Recommended By Microsoft. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. For questions and answers about anti-spam protection, see Anti-spam protection FAQ. It is true that Office 365 based environment support SPF but its imperative to emphasize that Office 365 (Exchange Online and EOP) is not configured anything automatically! ASF specifically targets these properties because they're commonly found in spam. 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. Great article. I always try to make my reviews, articles and how-to's, unbiased, complete and based on my own expierence. 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. This change should reduce the risk of SharePoint Online notification messages ending up in the Junk Email folder. 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? Creating multiple records causes a round robin situation and SPF will fail. Use the syntax information in this article to form the SPF TXT record for your custom domain. Enforcement rule is usually one of the following: Indicates hard fail. Go to Create DNS records for Office 365, and then select the link for your DNS host. You can only have one SPF TXT record for a domain. 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. Microsoft itself first adopted the new email authentication requirements several weeks before deploying it to customers. Include the following domain name: spf.protection.outlook.com. This setting combines an SPF check with a Sender ID check to help protect against message headers that contain forged senders. Q5: Where is the information about the result from the SPF sender verification test stored? The SPF Record is structured in such a way that you can easily add or remove mail systems to or from the record. Setting up SPF in Office 365 means you need to create an SPF record that specifies all your legitimate outgoing email hosts, and publish it in the DNS. To defend against these, once you've set up SPF, you should configure DKIM and DMARC for Office 365. 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. Soft fail. When you want to use your own domain name in Office 365 you will need to create an SPF record. 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. In this phase, we are only capturing event in which the E-mail address of the sender uses the domain name of our organization, and also; the result from the SPF sender verification test is Fail. An SPF record is required for spoofed e-mail prevention and anti-spam control. You add an SPF TXT record that lists the Office 365 messaging servers as legitimate mail servers for your domain. Edit Default > advanced optioins > Mark as Spam > SPF record: hard fail: Off. 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. Misconception 3: In Office 365 and Exchange Online based environment the SPF protection mechanism is automatically activated. . (Yahoo, AOL, Netscape), and now even Apple. However, there are some cases where you may need to update your SPF TXT record in DNS. In each of the above scenarios, the event in which the SPF sender verification test ended with SPF = Fail result is not good. 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. If you have a hybrid configuration (some mailboxes in the cloud, and . This ASF setting is no longer required. A good option could be, implementing the required policy in two phases-. For example, contoso.com might want to include all of the IP addresses of the mail servers from contoso.net and contoso.org, which it also owns. For example, the company MailChimp has set up servers.mcsv.net. What happens to the message is determined by the Test mode (TestModeAction) value: The following Increase spam score ASF settings result in an increase in spam score and therefore a higher chance of getting marked as spam with a spam confidence level (SCL) of 5 or 6, which corresponds to a Spam filter verdict and the corresponding action in anti-spam policies. For more information, see Configure anti-spam policies in EOP. Best thing to do is report the message via the Junk add-in and open a support case to have it properly investigated. Email advertisements often include this tag to solicit information from the recipient. Even in a scenario in which the mail infrastructure of the other side support SPF, in case that the SPF verification test marked as Fail, we cannot be sure that the spoofed E-mail will be blocked. 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). (e.g., domain alignment for SPF); d - send only if DKIM fails; s - send only when SPF fails. The E-mail message is a spoofed E-mail message that poses a risk of attacking our organization users. I am using Cloudflare, if you dont know how to change or add DNS records, then contact your hosting provider. We cannot be sure if the mail infrastructure of the other side support SPF, and if he implements an SPF sender verification test. As mentioned, the SPF sender verification test just stamp the E-mail message with information about the SPF test result. An SPF record is used to identify which mail servers (or systems) are allowed to send mail on your behalf. When this mechanism is evaluated, any IP address will cause SPF to return a fail result. All SPF TXT records start with this value, Office 365 Germany, Microsoft Cloud Germany only, On-premises email system. You need some information to make the record. Use the 90-day Defender for Office 365 trial at the Microsoft 365 Defender portal trials hub. Sender Policy Framework, or SPF, is an email authentication technique that helps protect email senders and recipients from spam, phishing and spoofing. 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. 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? For example, Exchange Online Protection plus another email system. 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. SPF enables receiving mail servers to authenticate whether an email message was sent from an authorized mail server - but only when the domain owner's SPF record is valid. 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. 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. You can use nslookup to view your DNS records, including your SPF TXT record. Enabling one or more of the ASF settings is an aggressive approach to spam filtering. Domain names to use for all third-party domains that you need to include in your SPF TXT record. Conditional Sender ID filtering: hard fail. Next, see Use DMARC to validate email in Microsoft 365. 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. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. 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. 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. 01:13 AM When this setting is enabled, any message that hard fails a conditional Sender ID check is marked as spam. Included in those records is the Office 365 SPF Record. A1: A Spoof mail attack implemented when a hostile element, uses a seemingly legitimate sender identity. If it finds another include statement within the records for contoso.net or contoso.org, it will follow those too. The presence of filtered messages in quarantine. If you go over that limit with your include, a-records an more, mxtoolbox will show up an error! You can't report messages that are filtered by ASF as false positives. Do nothing, that is, don't mark the message envelope. The reason could be a problem with the SPF record syntax, a specific mail flow, such as E-mail forwarding that leads to this result, and so on. Microsoft suggests that the SPF of Spambrella gets added to the domain's SPF. As of October 2018, spoof intelligence is available to all organizations with mailboxes in Exchange Online, and standalone EOP organizations without Exchange Online mailboxes. 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! You need all three in a valid SPF TXT record. 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. . This tool checks your complete SPF record is valid. 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. 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. Despite my preference for using Exchange rule as preferred tool for enforcing the required SPF policy, I would also like to mention an option that is available for Office 365 customers, which their mail infrastructure based on Exchange Online and EOP (Exchange Online Protection). 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. 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. The setting is located at Exchange admin Center > protection > spam filter > double click Default > advanced options > set SPF record: hard fail: off . 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. 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. LazyAdmin.nl is compensated for referring traffic and business to these companies at no expense to you. 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. Gather this information: The SPF TXT record for your custom domain, if one exists. SPF discourages cybercriminals from spoofing your domain, spam filters will be less likely to blacklist it. 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. But it doesnt verify or list the complete record. 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. Include the following domain name: spf.protection.outlook.com. 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. Basically, SPF, along with DKIM, DMARC, and other technologies supported by Office 365, help prevent spoofing and phishing. By analyzing the information thats collected, we can achieve the following objectives: 1. 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.. DKIM is the second step in protecting your mail domain against spoofing and phishing attempts. 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. A great toolbox to verify DNS-related records is MXToolbox. SPF identifies which mail servers are allowed to send mail on your behalf. 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. To work around this problem, use SPF with other email authentication methods such as DKIM and DMARC. For example, in case that we need to Impose a strict security policy, we will not be willing to take the risk, and in such scenario, we will block the E-mail message, send the E-mail to quarantine or forward the E-mail to a designated person that will need to examine the E-mail and decide if he wants to release the E-mail or not. Attackers will adapt to use other techniques (for example, compromised accounts or accounts in free email services). The answer is that as always; we need to avoid being too cautious vs. being too permissive. 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. Disable SPF Check On Office 365. We do not recommend disabling anti-spoofing protection. Include the following domain name: spf.protection.outlook.com. In other words, using SPF can improve our E-mail reputation. 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). To be able to get a clearer view of the different SPF = Fail scenarios, lets review the two types of SPF = Fail events. Misconception 1: Using SPF will protect our organization from every scenario in which hostile element abuses our organizational identity. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. You can list multiple outbound mail servers. 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. The first one reads the "Received-SPF" line in the header information and if it says "SPF=Fail" it sends the message to quarantine. 2. Refresh the DNS records page in Microsoft 365 Admin Center to verify the settings.The status of the TXT record will be listed as Ok when you have configured it correctly. However, anti-phishing protection works much better to detect these other types of phishing methods. How to enforce SPF fail policy in Office 365 (Exchange Online) based environment, The main two purposes of using SPF mechanism, Scenario 1: Improve our E-mail reputation (domain name), Scenario 2: Incoming mail | Protect our users from Spoof mail attack, The popular misconception relating to SPF standard. This article describes how you form your SPF TXT record and provides best practices for working with the services in Microsoft 365. office 365 mail SPF Fail but still delivered Hello today i received mail from my organization. Login at admin.microsoft.com, Expand Settings and select Domains Select your custom Domain (not the
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