SPF records are TXT type records that include all the IP addresses and mail servers that your employees and third-party vendors use to send emails on your behalf while operating your business domain name. This prevents phishing, spoofing, identity theft, and spam attacks that hackers could otherwise plan easily and jeopardize your company’s reputation and market value.
An SPF record is a bit complicated to manage as it should be updated if a new IP address is included or removed. The improper use of syntax (mechanisms, qualifiers, and modifiers) causes SPF validation errors, which leads to SPF authentication issues. Invalid or erroneous SPF DNS records are useless; they drive recipients’ servers into misidentifying even genuine emails as fraudulent and placing them in the spam folder or outrightly rejecting their entry.
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What is Exchange SPF Check?
Microsoft Exchange SPF check means running your SPF record through a tool that diagnoses it to highlight existing misconfigurations, typos, and syntax mistakes. This is one of the best practices as it allows domain owners to take adequate steps to rectify the spotted issues immediately to ensure no impact on email delivery and security.
If an SPF error isn’t fixed in time, it also affects the processing of DKIM and DMARC.
Common Problems Spotted During Microsoft Exchange SPF Checks
Your SPF record can get invalid due to one or more of the following issues-
Absence of an SPF TXT Record
An Exchange SPF check can’t be conducted by a tool if it hasn’t been able to locate any SPF record corresponding to the queried domain name. In such cases, you first need to ensure that your record exists; if it doesn’t, then you need to generate one.
Presence of Multiple SPF TXT Records
You can’t generate and publish multiple TXT records for a single domain and publish them on DNS. This invalidates all of them.
Exceeding the Lookup Limit
There can’t be more than 10 DNS lookups. You need to seek a solution to stay within the lookup limit.
Syntax, Misconfigurations, and Typos
This is hands down one of the common reasons that cause SPF validation errors. You need a technically sound person in your organization who has good syntax and configuration knowledge.
Not Adding all the IP Addresses
If any newly added in-house or third-party IP address or SMTP mail server is being used to send messages on your behalf, but still isn’t a part of your domain’s SPF record, then you’ll face delivery issues.
Please note that removing IP addresses that aren’t being used anymore is also important.
Use of the +all Tag
Every valid SPF record should end with the ‘all’ tag. It’s used to instruct receivers’ mailboxes about treating illegitimate email messages coming from your domain. You should use either ~all or -all tag as they define a softfail or fail, respectively. Using the +all tag (all pass) is a big mistake as it lets anybody (including a malicious sender) send a message from your domain, and it will always land in the primary inbox of the recipient unless a spam filtering tool finds it fraudulent.
Does Exchange Use SPF?
SPF records can be created for all the domains configured in Exchange. This averts spammers from exploiting domain names to retrieve information, which can tarnish the reputation of organizations.