diff --git a/exec/load/mailproc_util.js b/exec/load/mailproc_util.js
index 1592874ed381dc7861ec34abd4aa73ae5c3bd1d4..48e6e9345b2c5624fd59cd2391e4711546090d0b 100644
--- a/exec/load/mailproc_util.js
+++ b/exec/load/mailproc_util.js
@@ -17,7 +17,7 @@ function parse_msg_header(msgtxt)
 			break;
 		var match = msgtxt[i].match(/(\S+)\s*:\s*(.*)/);
 		if(match)
-			hdr[last_field=match[1]]=match[2];
+			hdr[last_field=match[1].toLowerCase()]=match[2];
 		else if(last_field)		// Folded header field
 			hdr[last_field]+=msgtxt[i];
 	}