From their website:
If your loan was recently transferred, please refer to your Goodbye and Welcome Letters for the name of your new servicer and for further details.
Please see below for payment address and contact information.
Midland Mortgage Company
Payment Address: Oklahoma City, OK 73126-8888
Written Inquiries: Midland Mortgage Customer Service P.O. Box 26648 Oklahoma City, OK 73126-0648 Customer Service: 800.654.4566
EverHome Mortgage Company
Payment Address: Atlanta, GA 30353-0579 Written Inquiries: Everhome Mortgage Company P.O. Box 2167 Jacksonville, FL 32232 Customer Service: 800.669.9721
CitiMortgage, Inc.
Payment Address: The Lakes, NV 88901-6175 Written Inquiries: CitiMortgage/Attn: Customer Research P.O. Box 9438 Gaithersburg, MD 20898-9438 Customer Service: 800.283.7918