proxmox.com

Checked 22 October 2026, 10:22 UTC · via 8.8.8.8
✗Problems found
14 passed 5 warnings 2 failed 3 info

SPF

warn

SPF record published

Found

Record
v=spf1 a mx ptr ip4:79.133.36.241/28 ip4:212.224.123.65/29 ip4:212.186.127.178/28 ip4:51.91.38.32/27 ip4:66.70.154.80/29 ip4:94.136.29.234/30 ip4:94.136.29.96/27 ip4:45.144.208.32/27 ip6:2a01:7e0:0:424::/64 ip6:2a02:ab8:308::/48 ip6:2a0f:8001:1:32::/64 ~all
DNS lookups
3 of 10
Void lookups
0 of 2

Checks

  • !
    Uses deprecated ptr mechanism
    The ptr mechanism in SPF records is deprecated due to performance issues and should be avoided.
    #1
  • ✓ 3 of 10 DNS lookups #2
    SPF record needs 3 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

No DMARC record found

Checks

  • ✗
    No DMARC record
    No DMARC record was found for this domain. DMARC is essential for preventing email spoofing. Add a DMARC record with p=reject or at least p=quarantine.
    #5

DKIM

fail

No keys found under the checked selectors

Found

Selectors
None found
_domainkey
NXDOMAIN

Checks

  • ✗
    No DKIM keys published
    _domainkey.proxmox.com does not exist (NXDOMAIN), so no DKIM keys are published. DKIM helps prevent email spoofing. Configure DKIM with your email service provider.
    #7

DNSSEC

warn

Not signed

Found

DNSKEY records
No (0)
DS at parent
No

Checks

  • !
    Not enabled
    DNSSEC is not enabled for this domain. Consider enabling DNSSEC to protect against DNS spoofing attacks.
    #8

MX

warn

1 mail server

Found

PriorityHostRecordsReverse DNS
10mail.proxmox.comA 94.136.29.106 A 212.186.127.180proxmox-new.maurer-it.com ✓ proxmox-new.maurer-it.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: mail.proxmox.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 2 MX addresss 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 hostTLSADNSSEC
mail.proxmox.comnone-

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