diff --git a/src/lib/letter.ts b/src/lib/letter.ts
index 5ae1703..7db2b9b 100644
--- a/src/lib/letter.ts
+++ b/src/lib/letter.ts
@@ -12,7 +12,7 @@ function parseTextPlainContent(mimeMessage: string) {
 
 	for (const body of boundaries) {
 		const headers: Record<string, string> = {};
-		const lines = body.split('\r\n');
+		const lines = body.split(/\r?\n/);
 		let isLookingForHeaders = true;
 		let content = '';
 		for (const line of lines) {
@@ -33,7 +33,12 @@ function parseTextPlainContent(mimeMessage: string) {
 
 	if (bodies.length === 0) return mimeMessage;
 
-	let chosenBody = bodies.find((body) => body.headers['Content-Type'] === 'text/plain');
+	if (bodies[0].headers['content-type']?.toLowerCase().startsWith('multipart/alternative'))
+		return parseTextPlainContent(bodies[0].content);
+
+	let chosenBody = bodies.find((body) =>
+		body.headers['content-type']?.toLowerCase()?.startsWith('text/plain')
+	);
 	if (!chosenBody) chosenBody = bodies[0];
 
 	const encoding = chosenBody.headers['content-transfer-encoding'];
@@ -43,7 +48,11 @@ function parseTextPlainContent(mimeMessage: string) {
 		case '7bit':
 			return chosenBody.content;
 		case 'base64':
-			return atob(chosenBody.content.replaceAll('\n', ''));
+			const raw = atob(chosenBody.content.replaceAll('\n', ''));
+			const bytes = new Uint8Array(raw.length);
+			for (let i = 0; i < raw.length; i++) bytes[i] = raw.charCodeAt(i);
+			const decoder = new TextDecoder('utf8');
+			return decoder.decode(bytes);
 		case 'quoted-printable':
 			return chosenBody.content
 				.replace(/=\r\n/g, '')