If your marketing or general business emails are consistently landing in spam folders instead of actual inboxes, the underlying cause is very often a missing or misconfigured email authentication setup — specifically involving SPF and DKIM. Neither of these requires you personally to become technical, but understanding what they each do helps you make sure they’re set up correctly by whoever manages your email systems.
What underlying problem SPF and DKIM solve
Email as a communication system was never originally built with strong security in mind from the start, which historically made it easy for anyone to send an email that falsely claims to be from someone else’s domain entirely — a common and long-standing method used for phishing attacks and spam. SPF and DKIM are two distinct, complementary mechanisms that let the domain receiving an incoming email verify whether a message came from where it claims to have come from, rather than being forged by someone else.
SPF: essentially a published list of who’s allowed to send email for your domain
SPF, which stands for Sender Policy Framework, is essentially a published list attached directly to your domain’s settings, explicitly naming which mail servers are officially authorized to send email on your business’s behalf. When another mail server receives an email claiming to be sent from your domain, it can check this published list directly — if the actual sending server isn’t included on it, that discrepancy is treated as a meaningful red flag suggesting the email might be forged or represent spam.
DKIM: a digital signature that proves an email wasn’t altered in transit
DKIM, short for DomainKeys Identified Mail, attaches a cryptographic digital signature to each outgoing email, which the receiving mail server can then verify against a corresponding public key published in your domain’s settings. This confirms two things simultaneously: that the email came from an authorized sender for that domain, and that its actual content wasn’t tampered with or altered at any point while it was in transit between servers.
Why this matters even if you personally never touch these settings yourself
Without correctly configured SPF and DKIM records in place, receiving mail servers have a harder time trusting that your outgoing emails are legitimate, which significantly increases the odds that they land in spam folders — even for entirely genuine, wanted business communication that a recipient wants to receive. This affects absolutely everything from bulk marketing emails down to simple, individual one-to-one messages sent from your own business domain.
DMARC works alongside SPF and DKIM as an additional layer
A third related mechanism, called DMARC, builds directly on top of SPF and DKIM by telling receiving mail servers specifically what to do when an incoming email fails either of those two checks — whether to deliver it anyway, quarantine it into spam, or reject it outright. Setting up DMARC correctly is a more advanced step, and it’s worth asking your email or marketing platform specifically whether it’s configured, since an improperly configured DMARC policy can block legitimate emails if it’s not set up carefully and correctly from the start.
What to do about all of this in practice
- If you use a business email provider or a dedicated marketing or CRM email platform, ask them directly and specifically whether SPF and DKIM are correctly configured for your particular sending domain — most reputable platforms provide clear setup instructions, or handle this configuration automatically during onboarding.
- If you’ve recently switched email providers or marketing platforms, this is one of the first things worth re-verifying immediately, since any change in your underlying sending infrastructure typically requires updating these specific domain records.
- Free online diagnostic tools exist that check your domain’s current SPF and DKIM status directly, without requiring any real technical expertise on your part to interpret the resulting report.
Deliverability is a ongoing concern, not a one-time technical setup task
Beyond SPF and DKIM specifically, overall deliverability is also meaningfully affected by genuine subscriber engagement (are people opening and clicking your emails, or consistently ignoring and marking them as spam instead), overall list quality, and sending consistency over time. Getting the underlying authentication basics right removes one of the single most common, fixable causes of poor deliverability — but it works best when paired alongside good ongoing list hygiene and wanted, relevant content, rather than being treated as a complete substitute for either of those things.
A quick way to sanity-check where your emails are landing
Beyond the technical diagnostic tools mentioned above, a simple practical check is sending a test email to a few different personal accounts across different providers and seeing where it lands — inbox, promotions tab, or spam folder. This won’t diagnose the specific underlying cause the way a dedicated tool will, but it gives you a fast, concrete, real-world sense of whether there’s a genuine problem worth investigating further with whoever manages your email sending setup.