Regular expression error in veryfing xml against xsd

I'm making verification xml against xsd and every regular expressions in xsd works well, except from that one:
'{http://ift.tt/1WBVvaA', attribute 'EmailPodmiotu': [facet 'pattern'] The value 'testecs@huzar.pl' is not accepted by the pattern '[A-Za-z0-9]+((\.|-|_)[A-Za-z0-9]+)*(@[A-Za-z0-9]+((\.|-|_)[A-Za-z0-9]+)*){1}'.'

Can someone tell me if this expression is wrong or i can add some functionality to my app?