I just updated last night to the latest beta of Outlook (15.11 150609) via the Microsoft auto update,
and 2 of my 5 pop accounts won't sync anymore and come up with an error.
An unknown error has occurred in Outlook.
Could not retrieve mail.
Error code: -1
Doing some testing, when I redo those accounts as imap instead of POP they do work.
Also, when comparing the settings of those 2 to my other POP accounts, they are setup the same way.
incoming (no SSL, port 110)
outgoing (no SSL, use incoming server authentication, override fault port to 587)
Those 2 accounts are hosted on a Eudora Mac-based EIMS Server, and from their client config instructions "use Challenge-Response MD5 authentication".
So I am not sure if it has something to do with that, as they did work before the latest update.
Any insight would help!