Previously, you had to add a different SPF TXT record to your custom domain if you also used SharePoint Online. Use one of these for each additional mail system: Common. Join the movement and receive our weekly Tech related newsletter. 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. 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. To be able to react to the SPF events such as SPF = none (a scenario in which the domain doesnt include a dedicated SPF record) or a scene of SPF = Fail (a scene in which the SPF sender verification test failed), we will need to define a written policy that will include our desirable action + configure our mail infrastructure to use this SPF policy.. SPF record types were deprecated by the Internet Engineering Task Force (IETF) in 2014. The event in which the SPF sender verification test result is Fail, can be realized in two main scenarios. Make sure that you include all mail systems in your SPF record, otherwise, mail sent from these systems will be listed as spam messages. 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. For questions and answers about anti-spam protection, see Anti-spam protection FAQ. . i check headers and see that spf failed. Messages that contain web bugs are marked as high confidence spam. In these examples, contoso.com is the sender and woodgrovebank.com is the receiver. 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. 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. The -all rule is recommended. 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. Most end users don't see this mark. This list is known as the SPF record. 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. Domain names to use for all third-party domains that you need to include in your SPF TXT record. Some services have other, more strict checks, but few go as far as EOP to block unauthenticated email and treat them as spoofed messages. For example, let's say that your custom domain contoso.com uses Office 365. SPF helps validate outbound email sent from your custom domain (is coming from who it says it is). If you're the sender's email admin, make sure the SPF records for your domain at your domain registrar are set up correctly. A9: The answer depends on the particular mail server or the mail security gateway that you are using. by This tag allows the embedding of different kinds of documents in an HTML document (for example, sounds, videos, or pictures). Edit Default > connection filtering > IP Allow list. 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. Test: ASF adds the corresponding X-header field to the message. Sender Policy Framework or SPF decides if a sender is authorized to send emails for any domain. EOP includes a default spam filter policy, which includes various options that enable us to harden the existing mail security policy. In our scenario, the organization domain name is o365info.com. The most important purpose of the learning/inspection mode phase is to help us to locate cracks and grooves in our mail infrastructure. Disabling the protection will allow more phishing and spam messages to be delivered in your organization. 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). 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. 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. 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. Messages that contain words from the sensitive word list in the subject or message body are marked as high confidence spam. Most of the mail infrastructures will leave this responsibility to us meaning the mail server administrator. SPF identifies which mail servers are allowed to send mail on your behalf. Q3: What is the purpose of the SPF mechanism? The reason for our confidence that the particular E-mail message has a very high chance to consider as Spoof mail is because we are the authority who is responsible for managing our mail infrastructure. 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. The enforcement rule indicates what the receiving mail system should do with mail sent from a server that isnt listed in the SPF record. If you have any questions, just drop a comment below. By rewriting the SMTP MAIL FROM, SRS can ensure that the forwarded message passes SPF at the next destination. 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. The reason that I prefer the option of Exchange rule is, that the Exchange rule is a very powerful tool that can be used to define a Tailor-made SPF policy that will suit the specific structure and the needs of the organization. You can only have one SPF TXT record for a domain. Solution: Did you try turning SPF record: hard fail on, on the default SPAM filter? 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. 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? Indicates soft fail. 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). This can be one of several values. In Office 365 based environment (Exchange Online and EOP) beside the option of using Exchange rule, we can use an additional option the spam filter policy. In case that your organization experiences a scenario in which your mail server IP address, In the current article and the next article: My E-mail appears as spam | Troubleshooting, In the current article, we will review how to deal with Spoof mail by creating, Your email address will not be published. If 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. This type of scenario, there is a high chance that we are experiencing a Spoof mail attack! 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. However, the industry is becoming more aware about issues with unauthenticated email, particularly because of the problem of phishing. Office 365 supports only one SPF record (a TXT record that defines SPF) for your domain. 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. 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. 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. Enforcement rule is usually one of the following: Indicates hard fail. If you've already set up mail for Office 365, then you have already included Microsoft's messaging servers in DNS as an SPF TXT record. This article was written by our team of experienced IT architects, consultants, and engineers. GoDaddy, Bluehost, web.com) & ask for help with DNS configuration of SPF (and any other email authentication method). A5: The information is stored in the E-mail header. Phishing emails Fail SPF but Arrive in Inbox Posted by enyr0py 2019-04-23T19:01:42Z. The answer is that as always; we need to avoid being too cautious vs. being too permissive. Add SPF Record As Recommended By Microsoft. Disable SPF Check On Office 365. 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. 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. Share. ip6 indicates that you're using IP version 6 addresses. 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? Feb 06 2023 No. More info about Internet Explorer and Microsoft Edge. 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 avoid this, you can create separate records for each subdomain. The Microsoft 365 Admin Center only verifies if include:spf.protection.outlook.com is included in the SPF record. Scenario 2. What are the possible options for the SPF test results? Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. In this article, I am going to explain how to create an Office 365 SPF record. Its Free. Ensure that you're familiar with the SPF syntax in the following table. Messages sent from Microsoft 365 to a recipient within Microsoft 365 will always pass SPF. 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. A scenario in which hostile element spoofs the identity of a legitimate recipient, and tries to attack our organization users. Next, see Use DMARC to validate email in Microsoft 365. 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. There are many free, online tools available that you can use to view the contents of your 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 . For example, Exchange Online Protection plus another email system. This is because the receiving server cannot validate that the message comes from an authorized messaging server. Messages that contain hyperlinks that redirect to TCP ports other than 80 (HTTP), 8080 (alternate HTTP), or 443 (HTTPS) are marked as spam. Specifically, the Mail From field that . And as usual, the answer is not as straightforward as we think. Include the following domain name: spf.protection.outlook.com. 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. A1: A Spoof mail attack implemented when a hostile element, uses a seemingly legitimate sender identity. Not every email that matches the following settings will be marked as spam. 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. 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. 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. In this category, we can put every event in which a legitimate E-mail message includes the value of SPF = Fail. By analyzing the information thats collected, we can achieve the following objectives: 1. If you still like to have a custom DNS records to route traffic to services from other providers after the office 365 migration, then create an SPF record for . 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. When Microsoft enabled this feature in 2018, some false positives happened (good messages were marked as bad). With a soft fail, this will get tagged as spam or suspicious. 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.