Technical checklist before sending

The technical checklist brings together five points that you can tick off before sending a newsletter: sender, authentication of the domain, unsubscribing in the text and in the email header, text version with alternative text, and a test send. It is meant for anyone who sends their own newsletters and does not want to overlook anything technical before clicking “Send”.

What is behind the points

SPF, DKIM and DMARC prove that an email really comes from your domain: SPF lists the servers that may send, DKIM signs the message, DMARC checks whether the visible sender address matches. The List-Unsubscribe header lets the mail program show its own “Unsubscribe” button; together with List-Unsubscribe-Post it signals one-click unsubscribe under RFC 8058. Gmail requires SPF, DKIM, DMARC and one-click unsubscribe from senders who send 5,000 or more messages a day to Gmail accounts. The text version is a plain-text version that is sent together with the HTML version; the recipient’s program shows the version it can display best (RFC 2046).

Sources

RFC 8058 – Signaling One-Click Functionality for List Email Headers, IETF / RFC Editor, Abschnitt 1 (Anti-Spam-Software ruft Adressen in Kopfzeilen automatisch ab), Abschnitt 3 (List-Unsubscribe-Post), Abschnitt 4 (DKIM-Signatur) (accessed on 25 October 2026)
Richtlinien für E-Mail-Absender (Gmail-Hilfe), Google, Abschnitte „Anforderungen an alle Absender“, „Anforderungen beim Senden von 5.000 oder mehr Nachrichten pro Tag“, „Sendevolumen langsam erhöhen“ (in German) (accessed on 2 November 2026)
RFC 2046 – Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types, IETF / RFC Editor, RFC vom November 1996, Abschnitt 5.1.4 (Alternative Subtype): „each of the body parts is an ‚alternative‘ version of the same information“; „In general, the best choice is the LAST part of a type supported by the recipient system's local environment.“ (accessed on 18 October 2026)

How to use it

Go through the list from top to bottom before every send.
Tick off the points you have completed; above the list you can see how many there are.
If you reload the page, the list is empty again – ready for the next send.

The checklist

Sender name and sender address under your own domain
SPF, DKIM and DMARC set up for the sender domain
Unsubscribe link in the text and List-Unsubscribe header with one-click unsubscribe (RFC 8058)
Text version included, images with alternative text
Test send to mailboxes with several providers

What the checklist does not check

Whether the points are really met. The list checks nothing itself. Whether SPF, DKIM and DMARC work is shown by the DMARC reports and the headers of a test email.
Content and appearance. Whether subject line, text and design fit and look good in all programs is only shown by the test send.
Legal matters. The list contains technical points only. What laws, court rulings and supervisory authorities say is quoted verbatim on the pages under Law.

Frequently asked questions

Is my progress stored? No. The ticks remain only while the page is open; there is no cookie, no local storage and no transmission.

Why are there no legal points in the list? This website reproduces legal matters only as verbatim quotations with a source and does not interpret them itself. A checklist with legal points would be such an interpretation; how we work is described under How we work.