Check and create SPF records to authorize senders.
SPF (Sender Policy Framework) is a DNS TXT record that lists which servers are allowed to send email on behalf of a domain. The receiving server compares the sender's IP address against that list and can flag the message as unauthorized when it does not match.
SPF Checker
Verify SPF record syntax and configuration.
Frequently Asked Questions about SPF
A domain uses SPF to specify which mail servers are authorized to send emails on its behalf. When an email is received, the recipient's server queries the SPF record of the sender's domain in DNS to verify if the mail server that sent the message is authorized.
It helps reduce the reception of unwanted mail (spam) and phishing. Improves the reputation and deliverability of the sender's domain. Protects recipients against fraudulent or malicious emails.
As of February 2024, configuring SPF, along with DKIM and DMARC, is an essential requirement for sending emails to Google and Yahoo servers. If SPF is not configured correctly, your emails will not be delivered.
It is created by adding a TXT entry to the domain's DNS, specifying the authorized mail servers. An example record is `v=spf1 ip4:192.168.0.1 -all`, which indicates that only the server with IP 192.168.0.1 is authorized to send emails from that domain.
The syntax defines which servers are authorized and how messages from unauthorized servers should be treated. It includes mechanisms such as `ip4`, `ip6`, `a`, `mx`, and `include`. It also uses qualifiers such as `+` (pass), `-` (fail), `~` (softfail), and `?` (neutral).
Most modern email servers support SPF. However, correct implementation is crucial to ensure that legitimate emails are not rejected or marked as spam.
If configured correctly, SPF should not negatively affect legitimate emails. It can improve confidence in emails sent from the domain and reduce the likelihood of them being marked as spam.
If an email fails SPF verification, it may be rejected, marked as spam, or subjected to additional scrutiny, depending on the receiving server's configuration and the sender domain's SPF policy.
Although SPF is an important tool, it alone is not sufficient for complete protection against phishing and spoofing. It is recommended to use it together with other email authentication protocols, such as DKIM and DMARC, for more robust security.
The challenges include ensuring that all legitimate mail servers are included in the SPF record. Avoiding exceeding the allowed DNS query limit. Updating the SPF record when mail servers change.
