o2.cz

01Overview 02DNS 03WHOIS 04Subdomains 05Email 06TLS

Checking SPF, DKIM, and DMARC

Loading domain report

Tools

DNS Lookup
WHOIS Lookup
RDAP Lookup
Subdomain Finder
Email Security Check
SSL and TLS Certificate Checker

digga is open source under AGPL 3.0.

GitHub

Checking SPF, DKIM, and DMARC

Email authentication

The basics are in place but can be hardened.

3Pass
1Warning
0Fail
2Not set

SPF

Warning

Authorizes which servers may send mail for the domain

SPF is published but could be tightened.

Policy: -all
DNS lookups: 10 / 10

Ends in -all (hardfail): unauthorized senders are rejected.
Uses 10 of 10 allowed DNS lookups. Close to the limit.

v=spf1 include:out.o2.cz a:aa.iol.cz ip4:90.176.151.28 include:spf.mailforce.cz include:spfe.targito.com include:o2.secar.cz ip4:74.121.51.138 include:spf.smartemailing.cz include:spf.finforce.cz -all

DKIM

Pass

Cryptographically signs outgoing mail (best-effort selector probe)

DKIM key published for 1 known selector.

Selectors: mail

Found a DKIM key at mail._domainkey.o2.cz

DMARC

Pass

Tells receivers what to do with mail that fails SPF and DKIM

DMARC is enforced.

Policy: p=quarantine
Coverage: 100%

Policy p=quarantine: failing mail is sent to spam.
Aggregate reports (rua) are configured.

v=DMARC1; p=quarantine; rua=mailto:[email protected],mailto:[email protected]; fo=1

MTA-STS

Not set

Enforces TLS for inbound mail and prevents downgrade attacks

No MTA-STS policy. Inbound mail can be delivered without TLS.

TLS-RPT

Not set

Receives reports about TLS delivery failures

No TLS-RPT record. You get no reports about failed TLS delivery.

BIMI

Pass

Displays your verified brand logo in supporting inboxes

BIMI is published.

Logo: https://vmc.digicert.com/bdcf68dc-6bf2-425d-a6df-bf4321caa4d2.svg
VMC: https://vmc.digicert.com/bdcf68dc-6bf2-425d-a6df-bf4321caa4d2.pem

A logo (l=) is published.
A Verified Mark Certificate (a=) is referenced.

v=BIMI1; l=https://vmc.digicert.com/bdcf68dc-6bf2-425d-a6df-bf4321caa4d2.svg; a=https://vmc.digicert.com/bdcf68dc-6bf2-425d-a6df-bf4321caa4d2.pem

Checks query live DNS over Cloudflare and the public MTA-STS policy endpoint. DKIM selectors cannot be listed from DNS, so DKIM detection probes common provider selectors only.