I have a LaserJet Pro MFP M521dn, in the past this unit was able to scan to email. But lately it gives an error of
Cannot connect to the SMTP server. Try a different port. e.g. 25, 587, 465.
I have did a factory reset, and then reinstalled the firmware that HP has on their website. I still get the same error. I have also setup the printer with a new IP address and tried a new port and switch. We are using the same smtp address and port # 25 on our other all in one units and these all in ones are working normal.