Hello, welcome, and thank you for choosing Just Answer.
Even though a corporation does not have activity (income or expenses), until you officially dissolve a corporation, you are still required to file a tax return. Lack of knowledge is not an acceptable excuse with the IRS.
It is typical for the IRS to contact a taxpayer 2-3 years later. That just seems to be the way they operate. If you can show reasonable cause for not filing, you may be able to negotiate or have the fees/penalties waived, (that would not include simply not knowing). Unfortunately, if you cannot show reasonable cause, more than likely, you will not be able to negotiate the fees/penalties.