I am facing the same issue as well. I have installed OpenEMM v6.2 in Windows XP and everything looks fine when I login. But after I create the mailings and sent it to the recipients in the list, none of them actually receive it. It says mailing being sent to the recipients but never sends it or it is probably getting stuck in the queue. Please let me know if you have figured out this issue. Your help would be really appreciated. Thanks.