diff --git a/public_html/lists/admin/init.php b/public_html/lists/admin/init.php
index d04aa36c8..21263da4b 100644
--- a/public_html/lists/admin/init.php
+++ b/public_html/lists/admin/init.php
@@ -216,6 +216,15 @@
 if (!isset($bounce_mailbox_purge_unprocessed)) {
     $bounce_mailbox_purge_unprocessed = true;
 }
+if (!isset($bounce_mailbox_maximum)) {
+    $bounce_mailbox_maximum = 100000;
+}
+if (!isset($bounce_rules_batch_size)) {
+    $bounce_rules_batch_size = 500;
+}
+if (!isset($bounce_mailbox_name)) {
+    $bounce_mailbox_name = 'INBOX';
+}
 
 // set some defaults if they are not specified
 if (!defined('REGISTER')) {
diff --git a/public_html/lists/admin/processbounces.php b/public_html/lists/admin/processbounces.php
index 5f8ad06b0..457ac7ec0 100644
--- a/public_html/lists/admin/processbounces.php
+++ b/public_html/lists/admin/processbounces.php
@@ -360,25 +360,36 @@ function processBounceData($bounceid, $msgid, $userid, $bounceDate = null)
 
 function processPop($server, $user, $password)
 {
-    $port = $GLOBALS['bounce_mailbox_port'];
+    global $bounce_mailbox_port, $bounce_mailbox_name, $bounce_mailbox_maximum;
+
+    $port = $bounce_mailbox_port;
     if (!$port) {
         $port = '110/pop3/notls';
     }
     set_time_limit(6000);
 
-    $link = imap_open('{'.$server.':'.$port.'}INBOX', $user, $password);
+    $mailboxNames = explode(',', $bounce_mailbox_name);
+    $report = '';
 
-    if (!$link) {
-        outputProcessBounce($GLOBALS['I18N']->get('Cannot create POP3 connection to')." $server: ".imap_last_error());
+    foreach ($mailboxNames as $mailboxName) {
+        $mailbox = sprintf('{%s:%s}%s', $server, $port, $mailboxName);
+        $link = imap_open($mailbox, $user, $password);
 
-        return false;
+        if (!$link) {
+            outputProcessBounce($GLOBALS['I18N']->get('Cannot create POP3 connection to')." $mailbox: ".imap_last_error());
+
+            return false;
+        }
+        $report .= processMessages($link, $bounce_mailbox_maximum);
     }
 
-    return processMessages($link, 100000);
+    return $report;
 }
 
 function processMbox($file)
 {
+    global $bounce_mailbox_maximum;
+
     set_time_limit(6000);
 
     if (!TEST) {
@@ -392,10 +403,10 @@ function processMbox($file)
         return false;
     }
 
-    return processMessages($link, 100000);
+    return processMessages($link, $bounce_mailbox_maximum);
 }
 
-function processMessages($link, $max = 3000)
+function processMessages($link, $max)
 {
     global $bounce_mailbox_purge_unprocessed, $bounce_mailbox_purge;
     $num = imap_num_msg($link);
@@ -554,7 +565,7 @@ function processMessages($link, $max = 3000)
     $bounceCount = Sql_Fetch_Row_Query(sprintf('select count(*) from %s', $GLOBALS['tables']['user_message_bounce']));
     $total = $bounceCount[0];
     $counter = 0;
-    $batchSize = 500; //# @TODO make a config, to allow tweaking on bigger systems
+    $batchSize = $bounce_rules_batch_size;
     while ($counter < $total) {
         $limit = ' limit '.$counter.', '.$batchSize;
         $counter += $batchSize;
diff --git a/public_html/lists/config/config_extended.php b/public_html/lists/config/config_extended.php
index 5274deea1..fe9129ed0 100644
--- a/public_html/lists/config/config_extended.php
+++ b/public_html/lists/config/config_extended.php
@@ -137,6 +137,18 @@
 // Set to 0 to received by mail bounce deletions in the advanced bounce processing report
 define('REPORT_DELETED_BOUNCES', 0);
 
+// The name of the POP3 mailbox
+// Multiple mailboxes can be specified separated by comma
+$bounce_mailbox_name = 'INBOX';
+
+// The maximum number of bounces to retrieve from the mailbox
+// This might need to be reduced if the processing times-out
+$bounce_mailbox_maximum = 100000;
+
+// When applying bounce rules the number of bounces to process in each batch
+// This might need to be reduced when there are a large number of bounces to process
+$bounce_rules_batch_size = 500;
+
 /*
 
 =========================================================================