Typically, lenders send Form 1098 to anyone who paid at least $600 in mortgage interest. A copy is also submitted to the IRS. If you did not receive one, you can still take the deduction by getting the information from your end-of-year mortgage statement.
You can call your lender's customer service line for a replacement 1098 form. Also, many times, you can log into your lenders website and retrieve your statement there. Verify the lender has your correct mailing address if you are not living in the home.