mda = ./mda-lmtp --addr=.test-sock --addr_network=unix \
        -to_puny -f fröm -d xn--t < test-email
mda <- cannot puny-encode recipient: idna: invalid label "t"
mda wait 2

mda = ./mda-lmtp --addr=.test-sock --addr_network=unix \
        -to_puny -f xn--f -d to < test-email
mda <- cannot puny-encode from: idna: invalid label "f"
mda wait 2