Microsoft-365-L1-Desktop-Support-guide

This article is designed as a practical, real-world L1 Desktop Support guide focused on troubleshooting Microsoft Outlook within a Microsoft 365 and Exchange Online environment. The goal is to help support engineers understand not just what to fix, but how to think during real helpdesk scenarios — from basic configuration to admin-level checks. Each section is structured around common ticket categories faced in enterprise environments. Whether you are preparing for an IT support role, improving troubleshooting workflow, or strengthening Microsoft 365 operational knowledge, this series will provide structured, actionable guidance. The content bridges the gap between end-user issues and Microsoft 365 Admin Center/Exchange Online workflows used by support teams daily. Outlook License Issue

I will write article on each topic for single single blog -

I’ll break into real helpdesk categories:

1. Account & License Management
2. Outlook Configuration
3. Send/Receive Issues
4. Profile & OST/PST Issues
5. Performance Issues
6. Mailbox & Storage
7. Archive & Backup
8. Exchange Admin Checks
9. Authentication/Login Problems
10. Common Errors & Fixes

Today we will see step by step Account & License Management  

Account & License Management

New User Creation + License Assignment (Microsoft 365 Admin) When Ticket Comes: so New employee joined — need email & Outlook setup”. As per this scenario also user not able to use outlook because he don't have access so let see how we can assign outlook access. L1 Desktop Support

Scenario Understanding (First — What Happened?)

• If user had access before but not now, possible causes:
• Exchange Online license removed,
• Account disabled,
• Mailbox removed,
• Password expired / account locked,
• Conditional Access / Security policy,
• Role change → license reassigned,
• Azure AD sync issue 

 Step 1 - Verify in Microsoft 365 Admin Portal 

Login -  https://admin.microsoft.com   
Go to Users -> Active Users  

 
👤 Step 2 — Check Account Status

✅ Sign-in allowed = ON
✅ Account not blocked

If blocked
Click user → Unblock sign-in

🎫 Step 3 — Check License Assignment (MOST IMPORTANT)

Inside user profile
go to Licenses & Apps
Check:

✔ Microsoft 365 E3/E5
✔ Exchange Online
✔ Business Standard

If Exchange license OFF → Outlook stops working.


✅ Step 4 — Assign Outlook / Exchange License
Click:

Licenses and Apps → Assign License
Enable:

☑ Exchange Online
☑ Outlook Desktop Apps (if available)


Then Click - Save changes

⏳ Step 5 — Wait for Provisioning

Normally it will take 5-20 minutes and microsoft will recreate mailbox access.

📬 Step 6 — Verify Mailbox Exists (Exchange Admin Center)

So Go to: https://admin.exchange.microsoft.com
then navigate - Recipients -> Mailboxes

then Search user -> Check 
✔ Mailbox active
✔ Not soft deleted


🔐 Step 7 — If Mailbox Missing

then create Mailbox :

Recipients → Mailboxes → Add Mailbox
or reassign Exchange license again.


💻 Step 8 — User Side Fix (VERY IMPORTANT)

Ask user to:

Close Outlook and 
in windows users will open Control Panel → Mail (32-bit)
(shortcut you can create new profile)

then click on Show profiles
then click on Add button
write Outlook_new in profile Name and OK
and a popup will come
with the help of "Office 365 Email ID + Password"
and set Always use this profile

Say to Interviewer

Interviewer love this if you start with - As per ITIL approach ....

so according to

Step 1 - user verification 
step 2 - Initial L1 checks
step 3 - TroubleShooting
step 4 - Escalation 


First I will verify in Microsoft 365 Admin portal whether the user account is active or blocked. Then I will check license assignment under Active Users. If Exchange Online license is missing, I will assign it and wait for provisioning. After that I will verify mailbox availability in Exchange Admin Center. Finally I will ask user to create a new Outlook profile from Control Panel → Mail on their Windows system and → Show Profiles → Add a new profile and reconfigure Outlook to resolve local profile or OST corruption issues and eliminate local profile corruption issues. and re-login to restore access. Service Desk Troubleshooting


Note - 

 
Do NOT delete old profile immediately — keep as backup
New profile automatically creates new OST file
Ensure Outlook is closed before profile creation
After login → check Status Bar = Connected to Microsoft Exchange


thats why when OST file corrupted we will use Excahnge for outlook rebuild it from the server.

Here As soon as we add a new profile, the OST file will be automatically created, and in the host file.
because in (OST) - Offline storage table and creates a local, synchronized copy of your exchange, office 365 or IMAP mailbox to work offline.

Sync changes back to the server when online requires a server connection for full functionality. 

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