Homburger

homburger.ch

Industry: Consulting & audit
Headquarters: Zürich, Zurich
Type: private
Employees (approx.): 300
Checked on: 19 October 2026

70/100Grade B

Protection against forged senders: protected

Points per criterion

MX 10 / 10
SPF 15 / 15
DKIM 20 / 20
DMARC 25 / 25
DNSSEC 0 / 10
Transport (MTA-STS/DANE) 0 / 15
TLS-RPT 0 / 5

Industry avg.: 66.8 ▲ 3.2
Canton avg.: 53 ▲ 17
Overall avg.: 53.5 ▲ 16.5
Rank 19 of 45 in the industry

Findings

!DKIM key below 2048 bits

RSA-1024 is considered too weak (RFC 8301, M3AAWG). Rotate to 2048-bit keys.
!DNSSEC not enabled

Without DNSSEC, DNS answers can be forged in transit. DANE requires DNSSEC.
!No MTA-STS

Without MTA-STS (or DANE) inbound encryption is not enforced; an attacker on the path can downgrade to plain text.
!No TLS reporting (TLS-RPT)

Without TLS-RPT the organisation does not learn when senders fail to deliver encrypted.

Check live in the Mail DNS Check →

Who runs the mail?

Mailbox provider: Self-hosted / other
Provider jurisdiction: Switzerland · MX: CH
Detection confidence: 85 / 100
Microsoft tenant: Managed · Homburger AG
Tenant region: EU

Signals (5)

SPF	Microsoft 365	`include:spf.protection.outlook.com`
Domain verification	Microsoft 365	`MS=ms72347807`
Domain verification	Google Workspace	`google-site-verification=UcM7O0MC-YeTpwY`
Network	Swisscom	`AS3303 SWISSCOM - Swisscom (Schweiz) AG`
Entra ID	Microsoft 365	`Entra-ID-Tenant (Managed)`

MX servers

Pref	Host	IP	Network	Country	TLSA
10	`mail1.homburger.ch`	`194.209.123.132`	AS3303 SWISSCOM - Swisscom (Schweiz) AG	CH	–
20	`mail2.homburger.ch`	`212.243.165.114`	AS3303 SWISSCOM - Swisscom (Schweiz) AG	CH	–

SPF

v=spf1 mx a:mail1.homburger.ch a:mail2.homburger.ch include:spf.abacuscity.ch include:spf1-eu.vx-email.com include:spf.protection.outlook.com -all

all: -all
DNS lookups: 6 / 10
Includes: spf.abacuscity.chspf1-eu.vx-email.comspf.protection.outlook.com
Detected sending services: Microsoft 365

DMARC

v=DMARC1;p=reject;rua=mailto:postmaster@homburger.ch

Policy: p=reject
Subdomains (sp): inherits p=reject
Share (pct): 100 %
Alignment DKIM/SPF: relaxed / relaxed
Aggregate reports (rua): postmaster@homburger.ch

DKIM

Selector	Key	delegated to
`mail`	RSA 1024	–

Checked: 100 common selectors. Keys under custom selectors remain invisible.

Transport encryption

MTA-STS: missing
DANE: missing
DNSSEC: missing
TLS-RPT: missing
BIMI: missing

Verified services

From verification records in the domain TXT: services where the domain is verified.

Microsoft 365GoogleDocuSignBrevo

History

18 October 2026 Score 70 · DMARC reject

All changes of this organisation in the change log →

Raw data

homburger.ch. IN MX 10 mail1.homburger.ch.
homburger.ch. IN MX 20 mail2.homburger.ch.
homburger.ch. IN TXT "v=spf1 mx a:mail1.homburger.ch a:mail2.homburger.ch include:spf.abacuscity.ch include:spf1-eu.vx-email.com include:spf.protection.outlook.com -all"
_dmarc.homburger.ch. IN TXT "v=DMARC1;p=reject;rua=mailto:postmaster@homburger.ch"

More from this industry

← Back to overview