mastodon.nl

Checked 21 October 2026, 21:23 UTC · via 8.8.8.8
!Passed with warnings
29 passed 3 warnings 0 failed 1 info

SPF

pass

SPF record published

Found

Record
v=spf1 +mx include:_spf.protagio.nl -all
DNS lookups
2 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 2 of 10 DNS lookups #2
    SPF record needs 2 DNS lookups (limit is 10).
  • ✓ Ends with -all #3
    SPF record properly uses -all to restrict unauthorized senders.
  • ✓ Record published #6
    SPF record exists for this domain.
  • ✓ Single record #16
    Exactly one SPF record is published.
  • ✓ Valid syntax #25
    All SPF mechanisms and modifiers are valid.
  • ✓ No void lookups #26
    All include/redirect targets exist.
  • ✓ No overly broad IP ranges #27
    All ip4/ip6 ranges are narrow enough.

DMARC

warn

p=quarantine (_dmarc.mastodon.nl)

Found

Record
v=DMARC1; p=quarantine; rua=mailto:admin@mastodon.nl; ruf=mailto:admin@mastodon.nl; fo=1
Found at
_dmarc.mastodon.nl
TagValueMeaning
vDMARC1Version
pquarantinePolicy
ruamailto:admin@mastodon.nlAggregate report addresses
rufmailto:admin@mastodon.nlFailure report addresses
fo1Failure reporting options

Checks

  • !
    Policy: quarantine
    DMARC policy is set to 'quarantine'. Consider upgrading to 'reject' for stronger protection once you've verified legitimate emails are passing authentication.
    #4
  • ✓ Record published #5
    DMARC record exists for this domain.
  • ✓ Valid syntax #17
    DMARC record syntax is valid.
  • ✓ Applies to 100% of mail #18
    DMARC policy applies to all failing mail.
  • ✓ Aggregate reports enabled #19
    Aggregate reports are sent to: mailto:admin@mastodon.nl
  • ✓ Subdomain policy: quarantine #20
    Subdomains are covered by policy 'quarantine'.
  • ✓ Report addresses in own domain #29
    All report addresses are in your own organizational domain.

DKIM

pass

Selectors: default

Found

Selectors
default
_domainkey
NOERROR
SelectorKeyFlags
defaultRSA 4096 bits

Checks

  • ✓ Keys found: default #7
    DKIM keys found for this domain with selectors: default
  • ✓ Strong keys #23
    DKIM keys are strong enough: default: RSA 4096 bits.
  • ✓ No problematic flags #24
    No keys in test mode, revoked, or limited to SHA-1.

DNSSEC

pass

Signed, DS published at parent

Found

DNSKEY records
Yes (1)
DS at parent
Yes
Algorithms
ECDSAP256SHA256 (13)
Key tags
11292
Signatures valid until
29 October 2026, 00:00 UTC

Checks

  • ✓ Signed, DS published at parent #8
    DNSSEC is enabled for this domain (DNSKEY and DS present), providing additional security for DNS lookups.
  • ✓ Signatures valid until 2026-10-29 #21
    DNSKEY signatures are valid until 2026-10-29T00:00:00Z.

MX

pass

2 mail servers

Found

PriorityHostRecordsReverse DNS
10smtp1.protagio.nlA 95.215.185.160 AAAA 2a00:51c0::5fd7:b9a0smtp1.protagio.nl ✓ smtp1.protagio.nl ✓
10smtp2.protagio.nlA 95.215.189.20 AAAA 2a00:51c0::5fd7:bd14smtp2.protagio.nl ✓ smtp2.protagio.nl ✓

Checks

  • ✓ 2 MX records #9
    Found 2 MX records for this domain.
  • ✓ All hosts resolve #10
    All MX records resolve to valid IP addresses.
  • ✓ All hosts have IPv6 #11
    All MX records resolve to IPv6 addresses.
  • ✓ Redundant MX hosts #12
    Found 2 MX records, which provides redundancy for email delivery.
  • ✓ At most 5 MX records #13
    Found 2 MX records, which is within the recommended range (1-5).
  • ✓ No localhost targets #14
    No MX records pointing to localhost found.
  • ✓ No private IP addresses #15
    No MX records resolving to private IP addresses found.
  • ✓ No CNAME targets #22
    No MX records point to a CNAME.
  • ✓ Reverse DNS confirmed #30
    All 4 MX addresss have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 2 of 2 MX hosts

Found

DANE (TLSA records)

MX hostTLSADNSSEC
smtp1.protagio.nl3 1 2 d6271c0eee92300f… 3 1 2 5aa7ee0b76f3cbf6…Yes
smtp2.protagio.nl3 1 2 87acf0b8d7f6f287… 3 1 2 e0e6e8cc124fb441…Yes

Checks

  • !
    Not configured
    MTA-STS is not configured, so other mail servers fall back to unencrypted delivery when TLS fails or is stripped by an attacker. Publish a _mta-sts TXT record and a policy at https://mta-sts.<domain>/.well-known/mta-sts.txt.
    #32
  • !
    Not configured
    MTA-STS or DANE is used without TLS-RPT, so you get no reports when senders fail to deliver because of TLS problems. Publish _smtp._tls TXT "v=TLSRPTv1; rua=mailto:...".
    #35
  • ✓ DANE on all MX hosts #36
    All 2 MX hosts publish DNSSEC-validated TLSA records.

BIMI

info

No BIMI record

Checks

  • i
    Not configured
    BIMI shows your logo next to your mail in supporting mail clients. It requires DMARC enforcement.
    #38