Small offices
Find out why your office email lands in spam or your IP gets flagged
AdminKit's free tools let small offices check SPF, DKIM, DMARC, and exposed devices today, since a single misconfigured record or one compromised laptop or printer can quietly send your mail to spam or get your office IP blacklisted, with a guided blacklist check and quoted expert configuration from the Netbase team when you want it done for you.
Updated
At a glance
Part of the Email authentication cluster — more tools, guides and terms on email authentication.
The problem
Small offices often run their own domain for email, but SPF, DKIM, and DMARC records are either missing, copied from an old guide, or left half-configured after switching email providers. The result is mail that silently lands in spam, with no obvious error message pointing at the cause.
A separate problem is that a single compromised machine on an office network, maybe an old laptop or an unpatched printer, can send spam or other abusive traffic without anyone noticing until the office’s shared IP address ends up on a blacklist. By the time a blacklist causes visible delivery problems, the underlying cause may have been running for a while.
Office equipment like printers and network-attached storage (NAS) devices also sometimes gets exposed via UPnP, a feature that lets devices open ports on the router automatically, without anyone reviewing what got opened or why. The open ports on my IP check shows whether any of those commonly-exposed ports are reachable from outside right now. Small offices rarely have dedicated IT staff checking any of this on a regular basis.
Talk to an expert
Huy Nguyen (David), Founder & CEO, Netbase JSC
Ask how AdminKit fits small offices — setup, timeline, or pricing.
What can a small office check for free?
These tools check public DNS records and your office’s public-facing exposure; none of them need access to anything inside your network.
- Check your SPF record — confirms which servers are allowed to send mail for your domain.
- Check your DMARC record — shows whether you have a policy telling other mail servers what to do with mail that fails checks.
- Check your DKIM setup — verifies your mail is being signed in a way receivers can trust.
- Look up your mail server records — confirms mail is routing to the right place.
- Check your domain’s expiry and registration — an expired domain can take down mail and your website at once.
For a full walkthrough of how these three records work together, see the SPF, DKIM, and DMARC explained guide. If your office IP ends up on a blacklist, why is my IP blacklisted, and how do I get delisted covers finding the cause and requesting removal manually. And since an expired domain can take mail and your website down together, what happens when a domain expires explains the renewal timeline the whois check above is reading against. If your office runs more than one sending domain, or an ongoing transactional or marketing mail program rather than just a shared inbox, AdminKit for email deliverability teams covers the fuller SPF, DKIM, DMARC, MX and reverse-DNS checklist that scale of sending needs.
How does Netbase help an office go further?
AdminKit’s blacklist check walks you through confirming whether your office’s shared IP has been flagged. Netbase can set up AdminKit Protective DNS for your office as a custom engagement, filtering DNS for every device on the network, including printers, NAS devices, and staff laptops, rather than the one-time outside checks above. For offices that want a one-time expert pass rather than doing it themselves, AdminKit also offers a small-office network security configuration through services, offered as a quote since no fixed price is published.
The mail-authentication checks above only read public DNS records, the same ones any mail server already consults before accepting your email — they don’t touch anything inside your office network.
Remote-support software left reachable from the internet is another common small-office exposure — see RDP and VNC exposed to the internet for why direct exposure is high-risk and the zero-trust tunnel alternative.
This page is general guidance, not a security audit of your specific network — see our disclaimer for what AdminKit's guidance does and does not commit to.
Frequently asked questions
Why does our office email keep landing in recipients' spam folders?
The most common cause is missing or misconfigured SPF, DKIM, or DMARC records, which mail providers use to decide whether to trust your mail. The spf-check, dkim-check, and dmarc-check tools show your current setup in plain terms.
Can AdminKit see our internal office network or files?
No. The mail authentication tools only read public DNS records, the same records any mail server already checks before accepting your email. AdminKit doesn't see inside your office network unless you separately choose to point something at it, like changing DNS or installing an agent.
Our office IP got blacklisted. What do we do first?
Run the DNSBL lookup on AdminKit's blacklist check page to confirm which list flagged you, then use the why-is-my-ip-blacklisted guide to find out why. The cause is often one compromised machine on the network sending spam or abusive traffic — fixing that machine and requesting delisting from the specific blacklist is usually the next step.
How do we get device-level network protection for the office?
Netbase sets up AdminKit Protective DNS for your office as a custom engagement — talk to our team at /contact/. The free tools check your mail and exposure setup from outside; they don't monitor devices continuously.
Can AdminKit configure our office network for us?
AdminKit offers a services option for a one-time small-office network security configuration, offered as a quote since there's no fixed published price. The free tools are meant for self-service checks first.
More in the Email authentication cluster
Want AdminKit set up for you?
Tell us about your setup — our team will scope AdminKit for it and, if you need it, add hands-on expert help from Netbase.
How AdminKit works with you
- Delivered remotely — Netbase JSC, the company behind AdminKit, has worked with clients in 80 countries.
- Contracts and invoices are issued by Netbase JSC; payment goes to the company by bank transfer to Netbase JSC's company account or PayPal Business.
- Talk to the CEO, Huy Nguyen (David), directly on WhatsApp or by email at [email protected].