They will log in to their Outlook (2007, 2010, or 2013), have it open for a few seconds or try to send an email and they will get a "Enter Network Password" pop up.
The pop up is erratic, sometimes it's every 2 seconds or for other users it happens only once an hour.
All the Outlook accounts with this problem are POP3 profiles, clients with an Exchange account do NOT experience this issue.
Under every client's Account Settings > Logon Information, each has the box checked to "Remember Password" which should stop a log in prompt.
I suspect that there is issues with the mail servers, with changes through Office 365. My previous server settings for users were;
Incoming Mail Server: PODxxxxx.outlook.com
Outgoing Mail Server (SMTP): PODxxxxx.outlook.com
but I noticed changes through routing on Office 365 last month, April 2013 and adjusted my settings accordingly;
Incoming Mail Server: outlook.office365.com
This seemed to temporarily rectify the issue, but now the prompt is back and I'm at a loss for why.
I'd like to know what changes are being made to Office 365 that are causing this issue, as it's not any hardware or software issues locally.
1) On Windows 7 machines, running Credential Manager and deleted the credential for BLUPRDxxxx.mailbox.outlook.com. This seemed to work temporarily as well, as it would prompt for a password one time once logging back into Outlook and had no further issues. The pop up appeared the next day.
2) Logging into each users account online at https://login.microsoftonline.com/ , clicking on the Office 365 Settings "gear" symbol, downloads, desktop setup, and run through the download for updates. This also seemed to solve the issue yesterday but the pop up has reappeared today.
Any suggestions are welcome on other options to try.