Validate your Sender Policy Framework (SPF) record to ensure email deliverability and prevent spoofing.
SPF is just the first layer. ObserveOne provides full observability into your website's uptime and API health.
Side-by-side breakdowns, no fluff.
SPF (Sender Policy Framework) is an email authentication method that specifies which mail servers are authorized to send email on behalf of your domain.
SPF stops attackers from sending fake emails that appear to come from your organization.
Google and Yahoo now require SPF/DKIM/DMARC for all bulk senders to reach the inbox.
SPF is published as a single DNS TXT record listing which servers may send mail for your domain. When a receiving server gets a message, it reads that record and checks whether the sending IP is authorized. A pass supports your DMARC alignment; a fail tells the receiver the message may be spoofed.
SPF allows a maximum of 10 DNS lookups. Exceeding that limit produces a PermError, and receivers ignore the record entirely.
Publishing two or more SPF records on the same domain is invalid, and mail providers may fail the check outright. Merge every sender into one record.
Ending a record in +all authorizes anyone to send as your domain. Use ~all (softfail) or -all (hardfail) instead.
Forgetting an include: for a provider you actually send through, such as a marketing platform, silently drops that mail. Avoid the deprecated ptr mechanism too.
~all is a softfail: receivers accept the mail but flag it as suspicious. -all is a hardfail: receivers reject or bin mail from servers not listed. -all is stricter, while ~all is the common starting point until you confirm every legitimate sender is covered.
A record can parse cleanly yet still fail in practice. The two usual causes are exceeding the 10 DNS-lookup limit, which triggers a PermError so the record is ignored, and a missing include for a provider you actually send through.
Ten. Each include, a, mx, ptr, and exists mechanism counts toward the limit; going over produces a PermError and receivers treat the record as unusable.
No. A domain must publish exactly one SPF TXT record. Two or more make the result invalid, and many providers will fail the check outright. Merge every sender into a single record.