I e-filed 1040EZ instead of 1040NR. I later found out that the efiling service I used does not have 1040 NR. Can I efile 1040X and 1040NR through another site?
Is it possible to mail in the amended forms, or should I efile it because I efiled 1040EZ?
Thanks in advance.

Nonresident tax return can't be e-filed.
Also amended tax return can't be e-filed.