Trouble sending emails from U.S. to Poland...

I'm having trouble sending emails from the U.S. to a friend in Warsaw, and she is having problems sending emails to me.
We've spoke on the phone and the addresses seem to be correct, so I don't know what else could be causing this. She has a googlemail.com address, and I have a gmail address.

Has anyone else experienced a similar problem?
I appreciate any help.

Try having her get an gmail account.

Is there any error message? From my experience Yahoo is best for international emails (not as often blocked like other email systems).

Did you look in the spam folder?
The only times I did not receive email in my inbox were emails from people writing to me for the first time, but they were in the spam folder...

I think gmail is the best, it dont block any messages and on other side if it does then it puts them into the bulk folder. so try to have gmail id instead of hotmail or yahoo :)

get a polish email... like wp.pl, onet.pl, o2.pl works perfect for me:)
Hotmail is the worst. Gmail is really great, combined with picasa is awesome:)