file1.txt:
moonwalker@address.com
hansolo@address.com
anakinskywalker@address.com
obiwankenobi@address.com
darthvader@address.com

file2.txt:
@adress1.com
@adress2.com
@adress3.com
@adress4.com
@adress5.com

output.txt:
moonwalker@address4.com
hansolo@address1.com
anakinskywalker@address5.com
obiwankenobi@address2.com
darthvader@address3.com