Mail domain report: tbo.com

SPF

pass

SPF record published

Found

Record: v=spf1 include:spf.protection.outlook.com include:spf.travelinfomail.com include:mail.zendesk.com include:spf.zohomail360.com include:sendgrid.net include:amazonses.com include:spf.salesforce.com -all
DNS lookups: 10 of 10
Void lookups: 0 of 2

Checks

✓ No deprecated ptr mechanism #1

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

SPF record needs 10 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.tbo.com)

Found

Record: v=DMARC1; p=quarantine; sp=reject; pct=10; rua=mailto:dmarcreporttbo@tbo.com; ruf=mailto:dmarcreporttbo@tbo.com; aspf=r
Found at: _dmarc.tbo.com

Tag	Value	Meaning
v	DMARC1	Version
p	quarantine	Policy
sp	reject	Subdomain policy
pct	10	Percentage of mail the policy applies to
rua	mailto:dmarcreporttbo@tbo.com	Aggregate report addresses
ruf	mailto:dmarcreporttbo@tbo.com	Failure report addresses
aspf	r	SPF alignment (r = relaxed, s = strict)

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 10% of mail

DMARC policy only applies to 10% of failing mail (pct=10). Raise pct to 100 once you are confident in your setup.

#18
✓ Aggregate reports enabled #19

Aggregate reports are sent to: mailto:dmarcreporttbo@tbo.com
✓ Subdomain policy: reject #20

Subdomains are covered by policy 'reject'.
✓ Report addresses in own domain #29

All report addresses are in your own organizational domain.

DKIM

warn

Selectors: selector1, selector2, s1, s2

Found

Selectors: selector1, selector2, s1, s2
_domainkey: NOERROR

Selector	Key	Flags
selector1	RSA 2048 bits
selector2	RSA 2048 bits
s1	RSA 2048 bits
s2	RSA 1024 bits

Checks

✓ Keys found: selector1, selector2, s1, s2 #7

DKIM keys found for this domain with selectors: selector1, selector2, 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

warn

Signed, but no DS at parent

Found

DNSKEY records: Yes (3)
DS at parent: No
Algorithms: ECDSAP256SHA256 (13)
Key tags: 60487, 5423, 6921
Signatures valid until: 22 October 2026, 18:00 UTC

Checks

!

Signed, but no DS at parent

The zone is signed (DNSKEY present) but the parent has no DS record, so the chain of trust is incomplete. Publish the DS record at your registrar.

#8
!

Signatures expire in 7h0m0s

DNSKEY signatures expire at 2026-10-22T18:00:00Z (in 7h0m0s). Check that re-signing works.

#21

MX

warn

1 mail server

Found

Priority	Host	Records	Reverse DNS
0	tbo-com.mail.protection.outlook.com	A 52.101.157.80 A 52.101.124.117 A 52.101.137.0 A 52.101.137.2 AAAA 2a01:111:f403:cc09:: AAAA 2a01:111:f403:cc1a::8 AAAA 2a01:111:f403:cc09::1 AAAA 2a01:111:f403:cc1f::4	mail-os8pr02cu00100.inbound.protection.outlook.com ✓ mail-tydpr03cu00105.inbound.protection.outlook.com ✓ mail-sg2pr03cu00500.inbound.protection.outlook.com ✓ no PTR mail-sg2pr03cu00500.inbound.protection.outlook.com ✓ mail-tydpr03cu00100.inbound.protection.outlook.com ✓ no PTR mail-os8pr02cu00104.inbound.protection.outlook.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.
✓ All hosts have IPv6 #11

All MX records resolve to IPv6 addresses.
!

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.
!

Addresses without reverse DNS

These MX addresses have no PTR record, which many receivers treat as a spam signal: 52.101.137.2 (tbo-com.mail.protection.outlook.com), 2a01:111:f403:cc09::1 (tbo-com.mail.protection.outlook.com). Ask your hosting provider to set one.

#30

TLS

warn

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

Found

DANE (TLSA records)

MX host	TLSA	DNSSEC
tbo-com.mail.protection.outlook.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