Good answers to your questions will require a personal jurisdiction legal analysis. Contact a defamation attorney. After gathering more information about your case, he or she can explain whether relevant personal jurisdiction law will enable you to litigate your lawsuit in Arizona rather than in the state where the person publishing defamatory falsehoods about you lives. If you cannot afford to hire an attorney to advise you, review the following appellate opinions using Google Scholar.
Calder v. Jones, 465 U.S. 783 (1984)
Keeton v. Hustler Magazine, Inc., 465 U.S. 770, 776 (1984)
Int’l Shoe Co. v. Wash., 326 U.S. 310 (1945)
Planning Group of Scottsdale v. Lake Mathews Mineral Props., Ltd., 226 Ariz. 262, 266, 246 P.3d 343, 346 (2011)
Batton v. Tennessee Farmers Mut. Ins. Co., 153 Ariz. 268, 273-274, 736 P.2d 2, 7-8 (1987)
You could also visit a good library to review chapters 12 and 13 of Rodney Smolla's treatise, Law of Defamation, 2d.
Mr. Hopkins is correct that this issue is a personal jurisdiction issue that needs to be discussed with a qualified civil litigator in AZ. The case law in this area is voluminous and constantly growing. As a result, you need to speak with a qualified attorney knowledgeable in the areas of internet related litigation and jurisdictional issues.
There are going to be personal jurisdiction issues that need to be addressed in determining where you can file suit. In addition, there may be other issues that need to be addressed as to which venue (if more than one is appropriate) gives you the better playing field for your suit. You need to consult an attorney with experience in the area.
This information is provided for general informational purposes and is not intended as legal advice. An attorney licensed in your jurisdiction can answer questions specific to your specific fact situation and provide you appropriate advice as necessary based on the specific facts of your matter and the jurisdiction in which you reside. If you are in Arizona and interested in discussing your matter further I can be reached at: (480) 838-9000 Campbell Law PC 1839 S. Alma School Road, Suite 275 Mesa, Arizona 85210
Know that defamation lawyers typically want a $5000.00 retainer just to begin work, and unless you've sustained a significant monetary loss, the costs could exceed the recovery.