this function 

misite.com/admin/mass-mailing 

gives this error 500: 

OW Debug - ExceptionMessage:Invalid argument `$email`File:/var/www/vhosts/misite.com/httpdocs/ow_system_plugins/base/classes/mail.phpLine:67Trace:#0 /var/www/vhosts/misite.com/httpdocs/ow_system_plugins/admin/controllers/mass_mailing.php(192): BASE_CLASS_Mail->addRecipientEmail('daniperez49-@ho...')#1 [internal function]: ADMIN_CTRL_MassMailing->index(Array)#2 /var/www/vhosts/misite.com/httpdocs/ow_core/request_handler.php(266): ReflectionMethod->invokeArgs(Object(ADMIN_CTRL_MassMailing), Array)#3 /var/www/vhosts/misite.com/httpdocs/ow_core/application.php(330): OW_RequestHandler->dispatch()#4 /var/www/vhosts/charlieprivee.es/httpdocs/index.php(65): OW_Application->handleRequest()#5 {main}Type:InvalidArgumentException

when it encounters an email with a hyphen before the @ 

These emails are valid at gmail.com, hotmail.com and others.