Scan to email problem

problem with scanning to email. I bought the xerox c405 and I have problems setting up the scan to email option. My company uses its smtp server and it works perfectly on all other printers and even on the xerox c405. With my colleague in the office, I installed another xerox c405 and set the scan to email option, but it sometimes works and sometimes throws out the error 027-504. Once everything is fine and the next 3-4 times the error 027-504.