Mail domain report: rcn.com

SPF

pass

SPF record published

Found

Record: v=spf1 include:_netblocks.eloqua.com ip4:207.172.4.0/24 ip4:207.172.157.0/24 ip4:208.58.56.0/24 ip4:198.183.9.0/24 ip4:146.115.106.224/27 ip4:207.172.159.1 ip4:66.235.59.86 ip4:130.250.132.170 ip4:130.250.130.230 a:mail.mutare.com a:mail.mutaresoftware.com include:_spf.rcn.syn-alias.com ~all
DNS lookups: 8 of 10
Void lookups: 0 of 2

Checks

✓ No deprecated ptr mechanism #1

No ptr mechanism found in SPF record.
✓ 8 of 10 DNS lookups #2

SPF record needs 8 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

fail

p=none (_dmarc.rcn.com)

Found

Record: v=DMARC1;p=none;sp=none;pct=100;rua=mailto:dmarc@eng.rcn.net;ruf=mailto:dmarc-rcn.com@eng.rcn.net
Found at: _dmarc.rcn.com
External report address: mailto:dmarc@eng.rcn.net (authorized)
External report address: mailto:dmarc-rcn.com@eng.rcn.net (authorized)

Tag	Value	Meaning
v	DMARC1	Version
p	none	Policy
sp	none	Subdomain policy
pct	100	Percentage of mail the policy applies to
rua	mailto:dmarc@eng.rcn.net	Aggregate report addresses
ruf	mailto:dmarc-rcn.com@eng.rcn.net	Failure report addresses

Checks

✗

Policy: none (monitoring only)

DMARC policy is set to 'none', which only monitors but doesn't protect against spoofing. Consider upgrading to 'quarantine' or ideally 'reject'.

#4
✓ Record published #5

DMARC record exists for this domain.
✓ Valid syntax #17

DMARC record syntax is valid.
✓ Aggregate reports enabled #19

Aggregate reports are sent to: mailto:dmarc@eng.rcn.net
✓ External report addresses authorized #29

Report addresses in other domains have published their authorization.

DKIM

warn

Selectors: s1, s2

Found

Selectors: s1, s2
_domainkey: NOERROR

Selector	Key	Flags
s1	RSA 2048 bits
s2	RSA 1024 bits

Checks

✓ Keys found: s1, s2 #7

DKIM keys found for this domain with selectors: s1, s2
!

1024-bit DKIM key

1024-bit RSA keys are the minimum and are considered weak today: s2 (1024 bits). Rotate to a 2048-bit key.

#23
✓ 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 (4)
DS at parent: Yes
Algorithms: RSASHA256 (8), ECDSAP256SHA256 (13)
Key tags: 49618, 50155, 23381, 25674
Signatures valid until: 21 November 2026, 04:04 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 2026-11-21 #21

DNSKEY signatures are valid until 2026-11-21T04:04:02Z.

MX

warn

1 mail server

Found

Priority	Host	Records	Reverse DNS
50	mx.rcn.com	A 129.159.122.98	mx.rcn.com ✓

Checks

✓ 1 MX record #9

Found 1 MX records for this domain.
✓ All hosts resolve #10

All MX records resolve to valid IP addresses.
!

Hosts without IPv6

The following MX hosts could not be resolved to IPv6 addresses: mx.rcn.com

#11
!

Single MX host, no backup

Only one MX record found. For better email reliability, consider adding at least one backup MX server.

#12
✓ At most 5 MX records #13

Found 1 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 1 MX address have a PTR record that resolves back to them.

TLS

warn

no MTA-STS · no TLS-RPT · DANE on 0 of 1 MX hosts

Found

DANE (TLSA records)

MX host	TLSA	DNSSEC
mx.rcn.com	none	-

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
i

Not configured

TLS-RPT lets senders report TLS delivery problems to you. It is most useful together with MTA-STS or DANE.

#35
i

Not used

No MX host publishes TLSA records. DANE lets senders verify your mail server's certificate through DNSSEC; it requires DNSSEC on the MX host's zone.

#36

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