DNS Shield
A single modified A record redirects your entire website. A deleted MX record kills your email. A hijacked NS record hands your domain to an attacker. You need to know the moment it happens.
7
Record types
30s
Check intervals
16+
Alert channels
PulseStack tracks all seven DNS record types. Each serves a different purpose and each has its own failure mode. Click a record type to learn what it does and what goes wrong when it changes.
Maps your domain to an IPv4 address. The most fundamental DNS record — if this is wrong, your website is unreachable.
Example
93.184.216.34
When this goes wrong
Hijacked A records redirect all website traffic to attacker-controlled servers
Free tool
Query A, AAAA, MX, NS, CNAME, TXT, and SOA records for any domain using Google and Cloudflare DNS resolvers. Results show all record values with query performance metrics.
Use this to audit your DNS configuration, verify changes after a migration, or investigate email delivery issues caused by missing SPF or MX records. The tool is free with no signup required.
For continuous monitoring that alerts you the moment any record changes, create a free PulseStack account. Each domain uses one monitor, and the free plan includes 50 monitors.
Add a domain, choose your alert channels, and PulseStack watches every record for changes.
DNS is attacked more often than most teams realise. Each attack type produces a different signature that PulseStack's change detection identifies immediately.
Attacker modifies DNS records at the registrar or nameserver level, redirecting your domain to their infrastructure.
A/NS record change detection
Fake DNS responses injected into resolver caches, sending users to malicious servers without touching your actual records.
Cross-resolver comparison
Abandoned CNAME records pointing to decommissioned cloud services claimed by an attacker.
CNAME target validation
MX records modified to route incoming email through attacker-controlled mail servers before forwarding to yours.
MX record change alerts
TXT records containing email authentication policies deleted or weakened, enabling spoofing of your domain.
TXT record monitoring
Misconfigured nameservers allowing anyone to download your entire DNS zone, revealing internal infrastructure.
SOA serial monitoring
Email protection
Email deliverability depends entirely on three DNS record types: SPF defines which servers can send email on your behalf, DKIM provides cryptographic signatures that prove messages are genuine, and DMARC tells receiving servers how to handle messages that fail SPF or DKIM checks. All three are stored as TXT records in your DNS zone.
A deleted SPF record means any server in the world can send email pretending to be your domain. A misconfigured DKIM record causes legitimate email to fail signature verification and get flagged as spam. A missing DMARC record removes your ability to control how receiving servers handle suspicious messages claiming to be from you.
These failures happen silently. Your outbound email continues to send normally from your mail server's perspective. But on the receiving end, messages are being rejected, quarantined, or marked as spam. The first sign of trouble is usually a customer saying they never received your invoice.
PulseStack monitors all TXT records and alerts you the moment SPF, DKIM, or DMARC records change or disappear. Combined with HTTP uptime monitoring and SSL certificate monitoring, you have complete visibility into every layer of your domain infrastructure.
Defines authorised mail servers
v=spf1 include:_spf.google.com ~all
Cryptographic email signatures
v=DKIM1; k=rsa; p=MIGfMA0G...
Policy for failed authentication
v=DMARC1; p=reject; rua=mailto:...
Mail server routing
10 mail.example.com
50 monitors free forever. Each domain uses one monitor. Upgrade when you need faster checks.
Most popular
£29/month
All plans include multi-location checks, incident management, and public status pages. Full plan comparison →
DNS monitoring covers your records. Add these for full-stack infrastructure visibility.
Everything you need to know about DNS record monitoring and change detection.
Add your domains, configure your alerts, and PulseStack watches every record for changes. Free for 50 monitors.
Start DNS monitoring free