Solved. There was string:
"%store_owner_name%" <email@@address>
in "Configuration" -> "MyStore" -> "E-mail from" field. Have doubts osCommerce assemble this string itself by instalation or initial configuration. After deleting everything but email address, it sending mails OK.
BTW: There was not outer <> in original configuration, only store_owner_name enclosed in doublequotes. Could the problem arise because doublequotes is special character on windows platform?