I have several users, that frequently stop receiving emails in their Outlook. The messages are being sent to their cellular devices just fine, and are showing up in Webmail, but not Outlook. Seems to be the same people more often than not. Any ideas?

I'm still having this problem with a handful of users, it's not everyone though, which is strange. I recently checked one user's log and this is what I'm seeing.... 2017-10-13 11:24:29.741 ME-EXXXX: (5580) [SMTP_Connect] Connected to server (mail.vontobels.com:25).Authentication failed against serve...

I'm currently using Outlook 2016 and Windows 10. I had to create the account through Mail in the control panel. Then selecting email accounts then clicking new. It showed MailEnable server in there as an option under other.

We currently have about 30 users on the MAPI client, and that number is going to be growing quickly. At my location, where the server is located, we have no problems with the sent folder. At a remote location, same company, same anti-virus software and Sonicwall firewall, the users lose their sent i...