Is it true that Abe Lincoln and Benito Juarez were pen pals?

Answer 1

Found this:
Though the two men never met, they did exchange correspondence and were admirers of each other. A message sent by Lincoln to Juárez on the eve of the Reform War expressed hope “for the liberty of…your government and its people.”
http://www.infopv.com/E.php3/ID/257

Found this from an interview of Dean Mahin, author of "One War at A Time", a Civil War History:

ALO: Three of your chapters review Union, Confederate, and postwar U.S. reactions to developments in Mexico, including the Mexican civil war, the French invasion, and Maximilian's Mexican "empire." What did Lincoln do to support the struggling republican government in Mexico?

Dean Mahin: Lincoln's minister in Mexico, Thomas Corwin, urged U.S. financial support for the Juarez government. The real story of aid to Juarez was deliberately masked by political maneuvering by Lincoln and diplomatic bluffing by Seward. The few historians who have written about U.S. relations with Mexico during the Civil War leave the impression that Lincoln and Seward wanted to provide financial support for Juarez but that the loan proposals were rejected by the Senate.

My research indicates that Lincoln wanted to provide the maximum possible moral and diplomatic support to the embattled republican government of Mexico - and wanted the Europeans and the Mexican conservatives to think that the U.S. was on the verge of substantial aid to Juarez - but in fact Lincoln was determined to avoid any military or financial commitment in Mexico. His only important speeches as a freshman Congressman in l847-48 had revealed how near James K. Polk had brought the nation to entrapment in a Mexican quagmire, and he was determined to avoid such a risk in the even more dangerous situation in Mexico in l861-62. But Lincoln maintained diplomatic support for Juarez and consistently refused to recognize the legitimacy of Maximilian's "imperial" government in Mexico.

Full Interview:
http://showcase.netins.net/web/creative/lincoln/books/mahin.htm

Answer 2

I would think that to be highly inlikely in that Juarez was in Mexico and Lincoln never crossed the Mississippi as far as I can tell. I am sure that if any correspondence did occur it would not have been called a pen pal as the mail was very erratic and one would often not get the mail addressed to them from this area of the world.