The issue is not on our end the issue is a global Quickbooks issue. The Quickbooks IP address was flagged as spam and is listed on spam lists like RBL and SpamCop. We can have it temporarily "whitelisted" on our end, but that is only temporary. Quickbooks IT needs to have their IP address delisted as spam. Many clients and vendors will no longer accept POs and invoices directly from Quickbooks, requiring us to save the POs or invoices and emailing them directly. Its a hassle and something that Quickbooks needs to address.