Microsoft 365 & Outlook Troubleshooting Guide

Free Troubleshooting Guide

Skip the forum threads. Go straight to the fix.

Straight fixes for the Outlook, Teams, Exchange, and Office 365 errors we get asked about the most, organized in one place instead of scattered across forum threads.

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Chicagoland's Microsoft 365 experts since 1994

Straight answers

Microsoft 365 and Outlook, answered directly

By Joe Engelking, CEO. Updated October 2026.

Why does Outlook keep asking for my password?

The usual causes are an old saved password in Windows Credential Manager, a recent password or multifactor change, or a damaged Outlook profile. Sign-in policy errors can also appear when your account’s multifactor settings do not meet your organization’s requirements. Start by checking that you can sign in at office.com, then use the guides below for the exact fix.

Why is Outlook not syncing or showing new email?

Check the status bar first. If it says Working Offline or Disconnected, the connection is the problem, not the mailbox. Other common causes are a full mailbox, a damaged profile or data file, a bad add-in, or an outdated Outlook version. Try Outlook in safe mode and sign in at office.com to tell a local problem from an account problem.

Does Microsoft 365 back up my email and files?

Not in the way most people assume. Microsoft keeps the service running and offers limited recovery windows for deleted items, but it does not replace a backup. Accidental deletion, ransomware, or a compromised account can still cause permanent loss, which is why we back up Microsoft 365 data separately from Microsoft.

What should a proper Office 365 migration include?

A complete migration moves mailboxes, calendars, contacts, and files, then sets up shared mailboxes and permissions, switches your mail routing at the right time, and secures accounts with multifactor authentication. It should be tested before staff rely on it and backed up afterward. Skipping the data move is how companies end up locked out of their old email.

What a proper Office 365 migration covers
Migration step	Why it matters	If it is skipped
Move old mail, calendars, and contacts	Staff keep everything they had	Old email is not available in the new setup
Move files and shared data	Nothing stays stranded on old systems	Files get left behind or lost in the move
Set up shared mailboxes and permissions	The right people see the right mail	Staff cannot reach shared inboxes
Switch mail routing at the right time	Email keeps arriving during the move	Mail is delayed or bounces
Secure accounts with multifactor authentication	Stops password-only takeovers	Accounts are exposed from day one
Back up Microsoft 365 data	You can recover from deletion or ransomware	There is only one copy of your data

Real example

What happens when a migration is left half done

Prairie Contractors in Frankfort, Illinois had an outside technician set up Office 365 and move them to the cloud. He failed midstream. Nothing had been migrated, and the team lost access to all of their old email.

We took over, ran the full migration properly, and set up Office 365 the right way. Then we added our managed IT approach: RMM automations, backups, security, and help desk. See how we run managed IT.

Joe Engelking, CEO

"LME has been doing this since 1994, and I keep seeing the same handful of Microsoft 365 problems come up again and again: a sign-in policy error, Outlook not syncing, Teams acting up. Most of them take five minutes once you know exactly what is actually broken. That is the whole idea behind this guide: skip the forum threads and go straight to the fix."

— Joe Engelking, CEO

Sign-In, MFA & Security Errors

Outlook & Email Issues

Microsoft Teams

SharePoint & OneDrive

Exchange, Migration & Device Setup

Still Stuck?

Some Problems Need More Than a Guide

If your Microsoft 365 setup keeps breaking in ways guides like this cannot fix, that is usually a sign of something deeper, like misconfigured licensing, DNS, or security policies. That is what we do for a living.