xfinity.com

Checked 22 October 2026, 11:34 UTC · via 8.8.8.8
!Passed with warnings
28 passed 6 warnings 0 failed

SPF

pass

SPF record published

Found

Record
v=spf1 -all
DNS lookups
0 of 10
Void lookups
0 of 2

Checks

  • ✓ No deprecated ptr mechanism #1
    No ptr mechanism found in SPF record.
  • ✓ 0 of 10 DNS lookups #2
    SPF record needs 0 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

pass

p=reject (_dmarc.xfinity.com)

Found

Record
v=DMARC1;p=reject;rua=mailto:dmarc-rua@dmarctest.comcast.net
Found at
_dmarc.xfinity.com
External report address
mailto:dmarc-rua@dmarctest.comcast.net (authorized)
TagValueMeaning
vDMARC1Version
prejectPolicy
ruamailto:dmarc-rua@dmarctest.comcast.netAggregate report addresses

Checks

  • ✓ Policy: reject #4
    DMARC policy is set to 'reject', which provides the strongest protection against email spoofing.
  • ✓ 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:dmarc-rua@dmarctest.comcast.net
  • ✓ Subdomain policy: reject #20
    Subdomains are covered by policy 'reject'.
  • ✓ External report addresses authorized #29
    Report addresses in other domains have published their authorization.

DKIM

warn

No keys found under the checked selectors

Found

Selectors
None found
_domainkey
NOERROR

Checks

  • !
    No key under common selectors
    The _domainkey name exists but no DKIM key was found under the common selectors. Selectors are provider-specific; check yours with -selector.
    #7

DNSSEC

warn

Signed, DS published at parent

Found

DNSKEY records
Yes (2)
DS at parent
Yes
Algorithms
ECDSAP256SHA256 (13)
Key tags
41802, 58223
Signatures valid until
27 October 2026, 09:00 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 expire in 117h0m0s
    DNSKEY signatures expire at 2026-10-27T09:00:21Z (in 117h0m0s). Check that re-signing works.
    #21

MX

warn

6 mail servers

Found

PriorityHostRecordsReverse DNS
5mx1a1.comcast.netA 96.103.145.163no PTR
5mx1c1.comcast.netA 96.102.18.147no PTR
5mx1h1.comcast.netA 96.102.157.181no PTR
5mx2a1.comcast.netA 96.103.145.162no PTR
5mx2c1.comcast.netA 96.102.18.146no PTR
5mx2h1.comcast.netA 96.102.157.180no PTR

Checks

  • ✓ 6 MX records #9
    Found 6 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: mx1a1.comcast.net, mx1c1.comcast.net, mx1h1.comcast.net, mx2a1.comcast.net, mx2c1.comcast.net, mx2h1.comcast.net
    #11
  • ✓ Redundant MX hosts #12
    Found 6 MX records, which provides redundancy for email delivery.
  • !
    More than 5 MX records
    Found 6 MX records, which is more than the recommended maximum of 5. Too many MX records may indicate a misconfiguration.
    #13
  • ✓ 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.
  • !
    Addresses without reverse DNS
    These MX addresses have no PTR record, which many receivers treat as a spam signal: 96.103.145.163 (mx1a1.comcast.net), 96.102.18.147 (mx1c1.comcast.net), 96.102.157.181 (mx1h1.comcast.net), 96.103.145.162 (mx2a1.comcast.net), 96.102.18.146 (mx2c1.comcast.net), 96.102.157.180 (mx2h1.comcast.net). Ask your hosting provider to set one.
    #30

TLS

warn

MTA-STS enforce · no TLS-RPT · DANE on 6 of 6 MX hosts

Found

MTA-STS record
v=STSv1; id=1667432290;
Policy URL
https://mta-sts.xfinity.com/.well-known/mta-sts.txt
Mode
enforce
Allowed MX
mx2c1.comcast.net, mx2h1.comcast.net, mx1a1.comcast.net, mx1h1.comcast.net, mx1c1.comcast.net, mx2a1.comcast.net, mx1.ge.comcast.net, mx2.ge.comcast.net, mx1.mxge.comcast.net, mx2.mxge.comcast.net
Max age
2592000 seconds

DANE (TLSA records)

MX hostTLSADNSSEC
mx1a1.comcast.net3 1 1 29b116c435937483…Yes
mx1c1.comcast.net3 1 1 29b116c435937483…Yes
mx1h1.comcast.net3 1 1 29b116c435937483…Yes
mx2a1.comcast.net3 1 1 29b116c435937483…Yes
mx2c1.comcast.net3 1 1 29b116c435937483…Yes
mx2h1.comcast.net3 1 1 29b116c435937483…Yes

Checks

  • ✓ Record published #32
    MTA-STS record found with id 1667432290.
  • ✓ Policy enforced #33
    The MTA-STS policy is enforced and cached for 720h0m0s.
  • ✓ All MX hosts covered #34
    Every MX host matches an mx: line of the MTA-STS policy.
  • !
    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 6 MX hosts publish DNSSEC-validated TLSA records.

BIMI

pass

https://postmaster.comcast.net/bimi_logos/xfinity.com.svg

Found

Record
v=BIMI1;a=https://postmaster.comcast.net/bimi_logos/xfinity.com.pem;l=https://postmaster.comcast.net/bimi_logos/xfinity.com.svg
Found at
default._bimi.xfinity.com
Logo
https://postmaster.comcast.net/bimi_logos/xfinity.com.svg
Certificate
https://postmaster.comcast.net/bimi_logos/xfinity.com.pem

Checks

  • ✓ Logo and certificate published #38
    BIMI logo: https://postmaster.comcast.net/bimi_logos/xfinity.com.svg; certificate: https://postmaster.comcast.net/bimi_logos/xfinity.com.pem
  • ✓ DMARC meets BIMI requirements #39
    DMARC is enforced on all mail, as BIMI requires.