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0xCAA82EE7

Microsoft 365 0xCAA82EE7 in Teams: server name could not be resolved

Verified with sources3 sourcesReviewed Oct 3, 2026
Technician coming? See the 3 steps they must show you

Risk level

Medium

Proceed carefully and stop if the check is unclear.

Urgency

Medium

Quick answer

Teams shows 0xCAA82EE7: the server name could not be resolved. Check you have internet; if the network works, IT should review the network, firewall and access to Microsoft 365 addresses.

Safety first

Stop and check this first

  • On the company network do not change DNS servers or proxy yourself: IT reviews the network setup against the Microsoft 365 destination list.

Safe checks you can perform

  • Internet connection
  • Teams client update
  • Reinstall Teams
  • Report the code to IT support

Leave these tasks to a qualified professional

  • Do not attempt this professional task: Network assessment towards Microsoft 365
  • Do not attempt this professional task: Teams Sign-in diagnostic
  • Do not attempt this professional task: Support request with logs

What a technician must be able to justify

Technician visit

These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.

These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.

  1. Network assessment towards Microsoft 365

    What they doThe IT technician uses Microsoft's network assessment tool and checks that firewall and proxy allow the Microsoft 365 URLs and IP ranges.

    They must show youthe assessment result.

    In writingthe blocked destination or port and the rule fixed.

  2. Teams Sign-in diagnostic

    What they doThe Microsoft 365 administrator runs the Teams Sign-in diagnostic in the admin center with the user's email, or the Teams Sign in test in the Microsoft Remote Connectivity Analyzer.

    They must show youthe test results.

    In writingthe issue found and the fix applied.

  3. Support request with logs

    What they doIf nothing works, the administrator collects Teams debug logs and opens a support request with the code from the sign-in screen.

    They must show youthe request number.

    In writingthe logs sent and Microsoft's reply.

Before accepting a part or repair

Nothing has been shown yet. Do not accept a part swap based on the code alone.

Follow these steps

Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.

  1. Internet connection

    No special tools

    Who:
    you.
    How:
    open any website and check it loads.
    Result that matters:
    whether you have internet access when Teams fails.
    If there is no connection:
    fix the network first; the code comes from the missing connection.
    If there is:
    the block may be a firewall or another app; IT reviews it.
    Evidence to keep:
    time of the failure and network used.

    Evidence: Why am I having trouble signing in to Microsoft Teams?

  2. Teams client update

    No special tools

    Who:
    you.
    How:
    in Teams, open the Settings and more menu next to your profile picture at the top right and select Check for updates. Install anything offered and sign in again.
    Result that matters:
    whether 0xCAA82EE7 goes away on the latest version.
    If you get in:
    the client was missing the latest update.
    If it repeats:
    go to the next check.
    Evidence to keep:
    Teams version before and after.

    Evidence: Fix Teams sign-in errors

  3. Reinstall Teams

    No special tools

    Who:
    you, or IT support on a managed device.
    How:
    uninstall Teams, open %appdata%\Microsoft, delete the Teams folder, download Teams again and install it. If you can, right-click the installer and Run as administrator.
    Result that matters:
    whether the error persists on a clean install.
    If you get in:
    the local install was damaged.
    If it persists:
    the cause is in the account, network or tenant; hand it to IT support.
    Evidence to keep:
    date of the reinstall and the code shown afterwards.

    Evidence: Fix Teams sign-in errors

  4. Report the code to IT support

    No special tools

    Who:
    you.
    How:
    note the status code at the bottom left of the window (0xCAA82EE7), the time and whether other Office apps fail too, and send it to your IT admin.
    Result that matters:
    IT getting the exact code.
    If IT finds the cause in the tenant or network:
    they fix it on their side.
    If not:
    IT opens a support request with Microsoft including debug logs.
    Evidence to keep:
    screenshot of the sign-in screen with the code.

    Evidence: Fix Teams sign-in errors · Why am I having trouble signing in to Microsoft Teams?

Still not solved

If the error persists, stop here. See what the technician must do and show you.

Where this code applies

A code is meaningful only inside the right product and version context.

Primary scope

System
Software and digital services
Brand
Microsoft 365
Product type
Office suites

Known code variants

  • CAA82EE7
  • Teams 0xCAA82EE7

What it means

Microsoft describes 0xCAA82EE7 as a server name that could not be resolved during Teams sign-in. It asks to check internet access and to verify with the network assessment tool that the network between the user and Microsoft can reach the Microsoft 365 URLs and IPs. The code does not say whether the fault is the local connection, name resolution on the network or a firewall block.

Warnings and stop conditions

  • Loweditorial warning

    On the company network do not change DNS servers or proxy yourself: IT reviews the network setup against the Microsoft 365 destination list.

    Evidence: Fix Teams sign-in errors · Microsoft 365 URLs and IP address ranges

Symptoms and causes

Probable causes · in order

  • No internet connectionPossible

    No website loads. Resolved once the network is back.

    Evidence: Fix Teams sign-in errors · Why am I having trouble signing in to Microsoft Teams?

  • Network or firewall preventing access to Microsoft 365 destinationsPossible

    Other sites load but Teams does not. IT confirms with the network assessment and URL list.

    Evidence: Fix Teams sign-in errors · Why am I having trouble signing in to Microsoft Teams? · Microsoft 365 URLs and IP address ranges

Virtual technician

Does 0xCAA82EE7 still appear after these checks?

Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.

Start diagnosis

Sources and technical references

  1. 1

    Fix Teams sign-in errors

    Microsoft · 2025 · official_doc

  2. 2

    Why am I having trouble signing in to Microsoft Teams?

    Microsoft · 2026 · official_doc

  3. 3

    Microsoft 365 URLs and IP address ranges

    Microsoft · 2026 · official_doc

Sources: Fix Teams sign-in errors · Why am I having trouble signing in to Microsoft Teams? · Microsoft 365 URLs and IP address rangesreviewed 2026-10-03 · verified

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