We had several Sharp MFP’s (MX-M364N, MX-M266N, and MX-M464N) that scan to email suddenly stopped working on. When trying to scan to email, the MFP would show a network error CE-00. Checking the settings, SMTP was correct, LDAP was correct, IP/DNS/Gateway was correct. Looking at the Job Log on one of the MFP’s I saw a line that the Result column said Send Error and Error Cause column said 80-0000.
I found the issue to be that the Default Sender Name and Reply Email Address field was blank. This was found under System Settings > Image Send Settings > Scan Settings. I entered in a name for the sender and an email address.
After clicking Submit, scan to email was working once again. Email servers are sometimes set to reject mail if it does not have all the header information needed such as sender name. I suspect Microsoft changed a setting on their end in support of better security.
I hope this helps. If so, let me know it!
This forum post was helpful during troubleshooting: Copy Tech Net