If you know the NAME of the AG employee you want to contact, his email address is usually going to be his name at "texasattorneygeneral.gov" (firstname.lastname@example.org). This is true whether he's in Dallas, Austin, Houston, San Antonio, or anywhere else.
Remember that it's possible that if his name is somewhat common (Joe Wilson, for example), they'll have him with a slightly different email address (such as "email@example.com"). Or you may have talked to him on the phone, and he introduced himself as "Jim," when his "official" name is James. But for 90% of the AG employees (including the attorneys and the upper-level management), the email address is
Want to send an email to Ken Paxton himself (the Attorney General of Texas)? Why not? What do you have to lose? Could their service get any worse? (Be sure to include your ten-digit case number.)