I have heard this story it seems over and over again, I also have been the topic of many email horror stories. They usually go like this
“I just setup a new server and within days we were on a corporate email blacklist, I contacted the company in question and asked why are we on your blacklist, why won’t you deliver our email. They shared with me an email log of thousands of emails being sent from my mail server through several legitimate email accounts. I ensured that my server was not an open relay so I asked these users, if they had indeed sent this many emails in one shot without any kind of unsubscribe link in the footer of their email. They had! I was so shocked, now what do I do?”
This is an uncomfortable and very perilous position. You want to allow your users to send email to get their job done however you as a systems administrator need to comply with the “Can Spam Act” passed by the FCC to ensure that email continues to flow. You also have companies out there who will block you for violating this act as a precaution on their part. All the while your users can not be bothered to learn about proper email procedures.