diff --git a/src/engine/rfc822/rfc822-message-data.vala b/src/engine/rfc822/rfc822-message-data.vala
index b114b2d7..d144e7db 100644
--- a/src/engine/rfc822/rfc822-message-data.vala
+++ b/src/engine/rfc822/rfc822-message-data.vala
@@ -30,13 +30,43 @@ public class Geary.RFC822.MessageIDList : Geary.Common.StringMessageData, Geary.
         
         string[] ids = value.split_set(" \n\r\t");
         foreach (string id in ids) {
-            id = id.strip();
-            if (!String.is_empty(id)) {
-                if (list == null)
-                    list = new Gee.ArrayList<MessageID>();
+            if (String.is_empty(id))
+                continue;
+            
+            // Have seen some mailers use commas between Message-IDs, meaning that the standard
+            // whitespace tokenizer is not sufficient; however, can't add the comma (or every other
+            // delimiter that mailers dream up) because it may be used within a Message-ID.  The
+            // only guarantee made of a Message-ID is that it's surrounded by angle brackets, so
+            // mark anything not an angle bracket as a space and strip
+            //
+            // NOTE: Seen at least one spamfilter mailer that imaginatively uses parens instead of
+            // angle brackets for its Message-IDs; accounting for that as well here.
+            int start = id.index_of_char('<');
+            if (start < 0)
+                start = id.index_of_char('(');
+            
+            int end = id.last_index_of_char('>');
+            if (end < 0)
+                end = id.last_index_of_char(')');
+            
+            // if either end not found or the end comes before the beginning, invalid Message-ID
+            if (start < 0 || end < 0 || (start >= end)) {
+                debug("Invalid Message-ID found: \"%s\"", id);
                 
-                list.add(new MessageID(id));
+                continue;
             }
+            
+            // take out the valid slice of the string
+            string valid = id.slice(start, end + 1);
+            assert(!String.is_empty(valid));
+            
+            if (id != valid)
+                debug("Corrected Message-ID: \"%s\" -> \"%s\"", id, valid);
+            
+            if (list == null)
+                list = new Gee.ArrayList<MessageID>();
+            
+            list.add(new MessageID(valid));
         }
     }
 }