Knowledge
How e-mail senders are protected – clearly explained, no expertise needed.
Why e-mails can be forgedAnyone can put someone else's sender on an e-mail. Why this is the case and what helps against it – explained simply.SPF – your domain's guest listWith SPF, you specify which servers are allowed to send e-mails for your domain. How the guest list works – and where it reaches its limits.DKIM – the seal on your e-mailsDKIM gives every genuine e-mail a digital signature from your domain. This lets the recipient recognise authenticity and changes.DMARC – the house rule for your domainDMARC determines what happens to forged e-mails from your domain and sends you a regular report. The three levels explained simply.How SPF, DKIM and DMARC work togetherWhat the recipient checks, when an e-mail is considered genuine – and four examples (newsletter, forwarding, mailing list, forgery).Transport encryption with MTA-STS and TLS-RPTHow to make sure that e-mails to your domain stay encrypted in transit – and how to find out when something goes wrong.Forwarding and mailing listsWhy forwarded e-mails fail the guest list but pass the seal – and why mailing lists play a special role.The history of e-mail protectionFrom the open e-mail of the 1980s via SPF, DKIM and DMARC to the obligations imposed by the large mail providers from 2024 – a brief overview.What is evolvingThe new DMARC standard from 2026, logos in the inbox with BIMI and a new seal called DKIM2 – which of these affects you today.Step by step to protection with igs.chHow igs.ch takes your domain to the reject level – from registration and tasks for your IT team to proof as a PDF.Working with your IT teamHow igs.ch sends tasks to your IT company or agency – by link, with no login needed for the external party, with instructions, a deadline and confirmation that everything has been fixed.