diff --git a/webmail/webmail.js b/webmail/webmail.js
index e2acc49121..8886db1474 100644
--- a/webmail/webmail.js
+++ b/webmail/webmail.js
@@ -2919,7 +2919,7 @@ const newMsgView = (miv, msglistView, listMailboxes, possibleLabels, messageLoad
 		'image/apng',
 		'image/svg+xml',
 	];
-	const isText = (a) => a.Part.MediaType.toLowerCase() === 'text';
+	const isText = (a) => ['text', 'message'].includes(a.Part.MediaType.toLowerCase());
 	const isImage = (a) => imageTypes.includes((a.Part.MediaType + '/' + a.Part.MediaSubType).toLowerCase());
 	const isPDF = (a) => (a.Part.MediaType + '/' + a.Part.MediaSubType).toLowerCase() === 'application/pdf';
 	const isViewable = (a) => isText(a) || isImage(a) || isPDF(a);
diff --git a/webmail/webmail.ts b/webmail/webmail.ts
index 13b7a7918c..6f21fa92c1 100644
--- a/webmail/webmail.ts
+++ b/webmail/webmail.ts
@@ -2466,7 +2466,7 @@ const newMsgView = (miv: MsgitemView, msglistView: MsglistView, listMailboxes: l
 		'image/apng',
 		'image/svg+xml',
 	]
-	const isText = (a: api.Attachment) => a.Part.MediaType.toLowerCase() === 'text'
+	const isText = (a: api.Attachment) => ['text', 'message'].includes(a.Part.MediaType.toLowerCase())
 	const isImage = (a: api.Attachment) => imageTypes.includes((a.Part.MediaType + '/' + a.Part.MediaSubType).toLowerCase())
 	const isPDF = (a: api.Attachment) => (a.Part.MediaType+'/'+a.Part.MediaSubType).toLowerCase() === 'application/pdf'
 	const isViewable = (a: api.Attachment) => isText(a) || isImage(a) || isPDF(a)