This is probably a thread suited for both this subforum and Webmastering/programming. We use a custom webapp for online training that has a feedback page built-in, all written in PHP. Whenever an email is made from the site the app uses the user's email address as the From address in the email header and sends it to our organization's email server. However, none of the emails come through. After a few months of back and forth with our Network Management Office, I realize the problem. Since the email is given a From of, say, email@example.com, and comes from a private server on a static IP (no domain name), our local email server can't verify the domain to the sender and trashes it as spam. Our techs refuse to white list this, so I've been forced to BCC all the email to my personal account, and manually forward it in. The server runs Red Hat Linux and sendmail. I'm not very comfortable with sendmail, and don't even know where to start. Basically, I need it to send emails that can legitimately enter our network. I tried setting From: to test@<ip> and that didn't work. The email came through as "Apache <apache@[hostname].local>". There are critical emails, and I'm breaking a few regs by having my personal account in the mix, so I'm trying to find a good solution.