Ebizmarts_AbandonedCart doesn't check whether a product that will be sent in an Abandoned Cart email is still available. This piece of code checks whether the product still exists, is enabled and has stock available (if stock is managed). If any of these 3 do not comply, the product is removed from the quote. Finally, we check whether there are …

abandonedcart_stock_check.php

<?php

/* Place this on line 117, right after foreach($collection as $quote) in app/code/community/Ebizmarts/AbandonedCart/Model/Cron.php */

foreach($quote->getAllVisibleItems() as $item) {
    $removeFromQuote = false;
    $product = Mage::getModel('catalog/product')->load($item->getProductId());
    if(!$product || $product->getStatus() == Mage_Catalog_Model_Product_Status::STATUS_DISABLED) 
    {
        Mage::log('AbandonedCart; ' . $product->getSku() .' is no longer present or enabled; remove from quote ' . $quote->getId() . ' for email',null,'Ebizmarts_AbandonedCart.log');
        $removeFromQuote = true;
    }
    $stock = $product->getStockItem();
    if(
        (
            $stock->getManageStock() ||
            ($stock->getUseConfigManageStock() && Mage::getStoreConfig('cataloginventory/item_options/manage_stock', $quote->getStoreId()))
        )
    && $stock->getQty() < $item->getQty())
    {
        Mage::log('AbandonedCart; ' . $product->getSku() .' is no longer in stock; remove from quote ' . $quote->getId() . ' for email',null,'Ebizmarts_AbandonedCart.log');
        $removeFromQuote = true;
    }
    if($removeFromQuote)
    {
        $quote->removeItem($item->getId());
    }
}
if(count($quote->getAllVisibleItems()) < 1)
{
    srand((double)microtime()*1000000);
    $token = md5(rand(0,9999999));
    $quote2 = Mage::getModel('sales/quote')->loadByIdWithoutStore($quote->getId());
    $quote2->setEbizmartsAbandonedcartCounter($quote2->getEbizmartsAbandonedcartCounter()+1);
    $quote2->setEbizmartsAbandonedcartToken($token);
    $quote2->save();
    continue;
}

This pull request was merged in the new MageMonkey version! ebizmarts/magemonkey#8 (comment)