Inmate mail goes through a processing facility. My postal mailing address is:

Katherine Seals # 02293338
Texas Department of Criminal Justice 
P.O. Box 660400
Dallas, TX 75266-0400

Do not send cash, personal checks or stamps.  The letter(s) inside must be addressed to the inmate on the envelope.
Mail must have a return address (as defined by the USPS ), including an identifiable last name.