Mail domain report: trybooking.com

SPF

pass

SPF record published

Found

Record: v=spf1 include:spf.protection.outlook.com include:mailgun.org include:spf.zoho.com include:transmail.net -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.trybooking.com)

Found

Record: v=DMARC1; p=none
Found at: _dmarc.trybooking.com

Tag	Value	Meaning
v	DMARC1	Version
p	none	Policy

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.
!

No aggregate reports (rua)

DMARC record has no rua tag, so you receive no aggregate reports about who sends mail as your domain. Add rua=mailto:...

#19

DKIM

warn

Selectors: default, google, mx

Found

Selectors: default, google, mx
_domainkey: NOERROR

Selector	Key	Flags
default	RSA 1024 bits
google	RSA 1024 bits
mx	RSA 1024 bits

Checks

✓ Keys found: default, google, mx #7

DKIM keys found for this domain with selectors: default, google, mx
!

1024-bit DKIM key

1024-bit RSA keys are the minimum and are considered weak today: default (1024 bits), google (1024 bits), mx (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

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

Priority	Host	Records	Reverse DNS
10	trybooking-com.mail.protection.outlook.com	A 52.101.149.2 A 52.101.151.0 A 52.101.149.9 A 52.101.149.1 AAAA 2a01:111:f403:cc33::1 AAAA 2a01:111:f403:cc31::3 AAAA 2a01:111:f403:cc31::1 AAAA 2a01:111:f403:cc31::8	mail-sy5pr01cu00902.inbound.protection.outlook.com ✓ mail-meupr01cu00200.inbound.protection.outlook.com ✓ mail-sy2pr01cu00501.inbound.protection.outlook.com ✓ mail-sy8pr01cu00101.inbound.protection.outlook.com ✓ mail-meupr01cu00301.inbound.protection.outlook.com ✓ mail-sy2pr01cu00503.inbound.protection.outlook.com ✓ mail-sy8pr01cu00101.inbound.protection.outlook.com ✓ mail-sy2pr01cu00600.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.
✓ Reverse DNS confirmed #30

All 8 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 host	TLSA	DNSSEC
trybooking-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

fail

https://trybooking.com/resources/TryBooking-BIMI-Icon.svg

Found

Record: v=BIMI1; l=https://trybooking.com/resources/TryBooking-BIMI-Icon.svg
Found at: default._bimi.trybooking.com
Logo: https://trybooking.com/resources/TryBooking-BIMI-Icon.svg

Checks

!

No certificate (a=)

The logo is published without a Verified Mark Certificate. Gmail and Apple Mail only show BIMI logos with a VMC or CMC; Yahoo shows it without one.

#38
✗

DMARC not strict enough for BIMI

Mail clients will not show the logo. BIMI requires DMARC p=quarantine or p=reject (now p=none), a subdomain policy other than sp=none.

#39