HTML und nicht HTML-Variante ( HTML und plain text)
Bilder integrieren / entfernen anstatt von extern (promato.de)
*Wenn Links dann von der gleichen Domain wie der E-Mailabsender ( schwierig) -> alternativ data Attribut und Base 64. Größe der Mail checken, möglichst nicht größer 100kb
*Viele Farbwechsel in unserem Footer -> Spammer Technik
Bessere Authentication: DKIM / SPF / DMARC
*SPF: Mail korrekt gesetzt ? Ausgang auch tatsächlich über die IP?
*DKIM: Signierung
Reputation of Domain and IP?
*https://senderscore.org/
*https://www.talosintelligence.com/reputation_center/lookup?search=213.135.2.138
*https://postmaster.google.com/
Unsubscribe-Link, wird geprüft wenn die Mail sich nach Newsletter oder Werbung darstellt
*
*
*Allgemeine Tipps:
*HTML und Plaintext,
*keine shortlinks,
*alt-Tags an allen Bildern,
*Colorcodes ausschreiben (000->000000),
*Links mit target _blank,
*nicht zu viele verschiedene Farben,
*Nur httpS-Links
*Wenige Farbwechsel
*Korrektes HTMl, alles schließen
*UTF-8 Metatag
*target blank bei Links
*
*
*E-Mailchecker:
*http://isnotspam.com/
*
*
Andere IP für Marketing und direkte Kundenmails

Probleme in der aktuellen Mail / Signatur:
*http-Verlinkung
*Bilder integriert
*font-Tags nicht immer korrekt beendet, font wird sowieso nicht mehr verwendet -> inline-css
*Plain Text- Part
*Signatur für HTML und Signatur für plaintext in Thunderbird
*

Freemail Auszug , Mail mit normaler Signatur:

47 +0100 (CET)
return-Path: h.maass@netfutura.de
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from [172.16.3.105] (unknown [62.54.176.1]) by smtp.netfutura.de (Postfix) with ESMTPSA id 8B6BC380D3F for <>; Mon, 19 Feb 2024 13:21:43 +0100 (CET)

DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=netfutura.de; s=mail; t=1708345303; bh=EWnmTHdoh5jLXeWDEx6YXVz9Z1TNf9HgjBTp1B3Ragk=; h=Date:To:From:Subject:From; b=Od7THq4RQc2cREQwxa5l9g3TibqxyyrBT+1tjaqkcEmemCJQIi69MYovpDR3b/k1A vFkRgNPAnNf61Ae5fA8mqkPv7FykLvWQ0ywBsJ4GKrx2I8sul7qItfIEFR+RNvTi6R 7/BDGumNe/iw65ezrxbowxgrcqWclDLX4JLjRnac=
multipart/alternative; boundary="------------5DbTUI2qyMyBC2Bpjn0SdkBj"
<e8bcdfc0-637a-43ae-941a-9f167edcdf05@netfutura.de>
Mon, 19 Feb 2024 13:21:43 +0100
1.0
Mozilla Thunderbird
de-DE
Holger Maaß <h.maass@netfutura.de>
Test
NO
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