Let me paint the picture...
I'm visiting with a client yesterday. I ask him if they received the three contact requests from the site this week? He says no. I check with the person responsible for handling those within his company, they've not received anything from the site in at least a month.
Hmmm, I say to myself. What could be wrong? I jump on one of the PCs and log into their web based email to make sure all is okay with the forwarding email addresses. It is.
I get back to the office and open up the confirmation page for that site and everything is in order. Run a couple of tests, all okay.
I then decide to drop in a CC and BCC into the confirmation file. I do a test. I receive my confirmation. The client sends me an email this morning confirming receipt of the contact request. In the process, they notice that there is a message in their deleted mail which came from the main email address that the contact form is addressed to.
Well, come to find out that the IT guy set up the filters and apparently included info@ addresses. All of the contact forms from their sites use the info@ for the default email.
To make a long story short. Check your email filters and make sure you've not filtered something of importance. If your clients have installed email filters, make sure they've configured them properly if they rely on contact forms from their site to generate leads. Fortunately for us, those filters have only been in place for a few weeks.