Is it a common problem for email messages sent through the site to not be delivered? On this ad, http://ar15.com/forums/topic.html?b=7&f=91&t=389930, I emailed the poster saying that I would take his item 2+ hours before the next person came along. A sent confirmation message arrived in my mailbox but he claims that he did not receive an email from me so, he sold it to someone else. Any thoughts? Thanks.