Starting last week we have been receiving e-mails (maybe 5-10 a day) that the subject is “Form Submission”. However the email is blank. There is no From or other information in the email.
Where are these e-mails coming from? Are these generated from our website or somewhere else? Any guidance you can provide would be helpful.
I checked your site and it looks like you are using the popular formmail.pl script.
Usually these type of emails are generated by badly wrote web-robots (search engine indexers, etc.) that are indexing your site and submitting the blank forms.
Another likely possiblilty is that they are spam-bot attempts to use your form to send out spam. I checked out your script and it is the latest version so you should be safe. Older versions of formmail.pl had a bug that allowed spam sending so there are all kinds of spam-bots out searching for exploitable formmail.pl scripts to exploit.
Again if you are using version 1.92 or above you should be safe. If you are using anything older, you need to upgrade ASAP!