{"id":2203,"date":"2026-11-10T13:26:00","date_gmt":"2026-11-10T12:26:00","guid":{"rendered":"https:\/\/www.mailfino.com\/?p=2203"},"modified":"2026-11-10T13:26:00","modified_gmt":"2026-11-10T12:26:00","slug":"was-ist-ein-email-header","status":"publish","type":"post","link":"https:\/\/www.mailfino.com\/en\/was-ist-ein-email-header\/","title":{"rendered":"What is an email header?"},"content":{"rendered":"<p class=\"wp-block-paragraph\">An email header is the technical section at the start of a message. It includes fields such as From, To, Date, and Subject. Mail servers can add details such as Received fields that record transport hops. Email clients typically show only a selection of these fields in the inbox.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"1200\" height=\"800\" src=\"https:\/\/www.mailfino.com\/wp-content\/uploads\/2026\/11\/mailfino-glossar-email-header-v1.webp\" alt=\"A magnifying glass enlarges an email\u2019s header fields.\" class=\"wp-image-2193\" srcset=\"https:\/\/www.mailfino.com\/wp-content\/uploads\/2026\/11\/mailfino-glossar-email-header-v1.webp 1200w, https:\/\/www.mailfino.com\/wp-content\/uploads\/2026\/11\/mailfino-glossar-email-header-v1-300x200.webp 300w, https:\/\/www.mailfino.com\/wp-content\/uploads\/2026\/11\/mailfino-glossar-email-header-v1-1024x683.webp 1024w, https:\/\/www.mailfino.com\/wp-content\/uploads\/2026\/11\/mailfino-glossar-email-header-v1-768x512.webp 768w, https:\/\/www.mailfino.com\/wp-content\/uploads\/2026\/11\/mailfino-glossar-email-header-v1-18x12.webp 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Which fields are useful?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Reply-To can specify a different address for replies. Received fields help trace the route of the message. Authentication-Results can report checks that a mail server performed. To interpret a field, consider which server added it.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Example of a delivery delay<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If a newsletter arrives late, open the original message in your email client. Timestamps in several Received fields can help you identify where time passed between transport hops. Before sharing a header, check whether it contains personal addresses or internal details.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Further reading<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n\n<li><a href=\"https:\/\/www.rfc-editor.org\/info\/rfc5322\/\" rel=\"noopener\">RFC 5322 on the Internet Message Format<\/a><\/li>\n\n\n\n<li><a href=\"\/en\/was-ist-smtp\/\">What is SMTP?<\/a><\/li>\n\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"\/en\/glossar\/\">Back to the email marketing glossary<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>Der E-Mail-Header ist der technische Kopf einer Nachricht. Er enth\u00e4lt Felder wie From, To, Date und Subject. Mailserver k\u00f6nnen weitere Angaben erg\u00e4nzen, etwa Received-Zeilen f\u00fcr Transportstationen. E-Mail-Programme zeigen im normalen Posteingang meist nur eine Auswahl dieser Felder. Welche Felder sind hilfreich? Reply-To kann eine abweichende Antwortadresse angeben. Received-Zeilen helfen, den Transportweg einzugrenzen. Authentication-Results kann Ergebnisse [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":2193,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2203","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-allgemein"],"_links":{"self":[{"href":"https:\/\/www.mailfino.com\/en\/wp-json\/wp\/v2\/posts\/2203","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mailfino.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mailfino.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mailfino.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mailfino.com\/en\/wp-json\/wp\/v2\/comments?post=2203"}],"version-history":[{"count":1,"href":"https:\/\/www.mailfino.com\/en\/wp-json\/wp\/v2\/posts\/2203\/revisions"}],"predecessor-version":[{"id":2214,"href":"https:\/\/www.mailfino.com\/en\/wp-json\/wp\/v2\/posts\/2203\/revisions\/2214"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mailfino.com\/en\/wp-json\/wp\/v2\/media\/2193"}],"wp:attachment":[{"href":"https:\/\/www.mailfino.com\/en\/wp-json\/wp\/v2\/media?parent=2203"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mailfino.com\/en\/wp-json\/wp\/v2\/categories?post=2203"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mailfino.com\/en\/wp-json\/wp\/v2\/tags?post=2203"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}