--- a/src/dnsbl.cpp	Sun Dec 18 17:19:50 2016 -0800
+++ b/src/dnsbl.cpp	Sun Dec 18 17:55:16 2016 -0800
@@ -324,7 +324,7 @@
             return ip.s_addr;
         }
     }
-    int n = strlen(question);
+    size_t n = strlen(question);
     if (question[n-1] == '.') {
         priv.my_write(question, n+1);   // write the question including the null terminator
     }
@@ -1104,18 +1104,16 @@
 const char *to_lower_string(const char *email);
 const char *to_lower_string(const char *email) {
     if (!email) return strdup("<>");
-    int n = strlen(email);
-    if (n == 0) return strdup("<>");
-    if (email[0] == '<') {
-        // assume it also ends with >
-        n -= 2;
-        if (n < 1) return strdup("<>");
-        email++;
-    }
-    if ((email[0] == '\'') && (email[n-1] == '\'') && (n > 2)) {
+    size_t n = strlen(email);
+    if ((n > 1) && (email[0] == '<') && (email[n-1] == '>')) {
         n -= 2;
         email++;
     }
+    if ((n > 1) && (email[0] == '\'') && (email[n-1] == '\'')) {
+        n -= 2;
+        email++;
+    }
+    if (n ==0) return strdup("<>");
     char *key = strdup(email);
     key[n] = '\0';
     for (int i=0; i<n; i++) key[i] = tolower(key[i]);
@@ -1458,7 +1456,7 @@
     char msg[maxlen];
     if ((priv.header_count < 4) || (strcasecmp(headerf, "from") == 0)) {
         snprintf(msg, sizeof(msg), "header %s: %s", headerf, headerv);
-        for (int i=0; i<strlen(msg); i++) {
+        for (size_t i=0; i<strlen(msg); i++) {
             if (msg[i] < 0x20) msg[i] = ' ';
         }
         my_syslog(&priv, msg);
@@ -1472,17 +1470,17 @@
             if (priv.dkim_ok) {
                 const int nmatch = 2;
                 regmatch_t match[nmatch];
-                int offset = 0;
+                char *msgo = msg;
                 while (true) {
-                    if (0 == regexec(&dkim_pattern, msg+offset, nmatch, match, 0)) {
+                    if (0 == regexec(&dkim_pattern, msgo, nmatch, match, 0)) {
                         int s1 = match[1].rm_so;    // domain
                         int e1 = match[1].rm_eo;
                         if (s1 != -1) {
-                            char save = msg[offset+e1];
-                            msg[offset+e1] = '\0';
-                            priv.dkim_signers.insert(strdup(msg+offset+s1));
-                            msg[offset+e1] = save;
-                            offset += e1 + 1;
+                            char save = msgo[e1];
+                            msgo[e1] = '\0';
+                            priv.dkim_signers.insert(strdup(msgo+s1));
+                            msgo[e1] = save;
+                            msgo += e1 + 1;
                         }
                         else break;
                     }
@@ -1490,6 +1488,8 @@
                 }
             }
         }
+    }
+
         if ((priv.header_count > 2) && (strcasecmp(headerf, "from"))) {
             const int nmatch = 2;
             regmatch_t match[nmatch];
@@ -1502,7 +1502,6 @@
                 }
             }
         }
-    }
 
     // headers that avoid autowhitelisting
     if (((strcasecmp(headerf, "precedence") == 0)   && (strcasecmp(headerv, "bulk") == 0)) ||