Key points at a glance
- Usually a technical problem is to blame, not the content of your emails.
- Missing or faulty SPF, DKIM and DMARC records are among the most common causes.
- Newsletter tools, webshops and accounting software also need to be set up for your domain.
Cause 1: SPF, DKIM or DMARC missing or wrong
Large mailbox providers such as Google, Yahoo and Microsoft now require senders to identify themselves. If DMARC is missing, SPF is invalid, or a service sends without DKIM, trust in your emails drops significantly.
- Sender identified?SPF, DKIM and DMARC are set up and pass.
- Server clean?Your mail server’s address is on no blacklist.
- Behaviour unremarkable?Steady volumes, few spam reports and bounces.
- InboxThen your email has a good chance of reaching the inbox.
Mandatory for bulk senders since 2024
Anyone sending more than 5,000 emails a day to Gmail or Yahoo addresses has needed SPF, DKIM and DMARC since 2024. Microsoft has required the same since 2025 for private Outlook and Hotmail addresses.
Cause 2: your mail server is on a blacklist
Blacklists collect IP addresses that spam has come from. If an account of yours was misused, or you share an address with others, your server can end up on one. Many recipients reject emails from listed addresses.
Cause 3: services send in your name
A newsletter tool, webshop or accounting software sends with your sender address but is not listed in SPF and doesn’t sign with DKIM for your domain. To recipients, these emails look like forgeries.
Free domain check
Is your company address protected?
Enter your domain or your email address. You see the result right here, with a traffic light and a grade from A to F.
You opened a link to a result. The check only starts when you click, always with the current state.
Privacy: if you enter an email address, we transmit only the domain; the part before the @ never leaves your browser. We use the domain only for this check of public DNS records and do not store it in plain text; we do not store the result. We store your IP address only as a checksum and for at most one day to curb abuse.
The quick check is based on public DNS data at the time of the query and does not replace a full review; no warranty.
Keep an eye on it continuously instead of checking once:
Book a free initial callMonitor your domain – 14 days freePrefer some help? Ask us to set it up- No commitment
- No credit card
- Ends on its own after 14 days
No-obligation request by email · price on request
What happens next
- Your email program opens a prepared request with your domain. Add your name and send it.
- We get back to you and discuss with you or your IT partner which records (SPF, DKIM, DMARC) are needed and what the setup costs.
- The setup needs access to the DNS management of your domain. We agree the handover with you – please never send us passwords by email.
- If you wish, DomainRadar then monitors your domain continuously and alerts you when something changes.
No email program opens? Write to us with your domain at info@domainradar.ch.
Good to know: this protection stops anyone forging exactly your domain. Against look-alike addresses, always confirm payment changes by phone.
All checks
Quick check based on public DNS records. Continuous monitoring also checks certificates, blocklists and your DMARC reports.
Your result as a PDF
As a report to keep or to forward to your IT.
Free and without an account: you confirm your address by email and can unsubscribe at any time.
Cause 4: behaviour and content
- Suddenly far more emails than usual, for example with a first newsletter.
- Many recipients mark your emails as spam; newsletters are missing a simple unsubscribe link.
- Address lists with outdated addresses that cause too many bounces.
Tip for your first newsletter
Send newsletters through a dedicated service and set up SPF and DKIM for it with your domain before the first mailing goes out.
What to do
- Check and fix SPF, DKIM and DMARC for every sending domain.
- List all services that send in your name and set up SPF and DKIM for each.
- Check blacklists and request delisting once the cause has been fixed.
- Handle bulk mailings through a dedicated service with a clean unsubscribe process.
How DomainRadar helps
DomainRadar continuously checks SPF, DKIM and DMARC, monitors the IP addresses of your mail servers against blacklists and shows in the DMARC reports which services send in your name and whether they are set up correctly.
The domain check stays free. Afterwards you test DomainRadar with all features for 14 days – no credit card, the trial ends on its own.