How to Resolve Outlook Cannot Connect to Online Microsoft 365 Error?
Summary: When your Microsoft Outlook is not connecting to the Online Microsoft 365, then you may face troubles while sending or receiving emails. Follow the solutions mentioned in this article to fix and resolve the ‘Outlook cannot connect to Microsoft 365 error. You will also understand about an OST to PST Converter software that can help convert mail items from inaccessible or orphaned OST files.
Microsoft Outlook is the default and preferred email and calendaring program for setting up and accessing a Microsoft 365 (sometimes called Exchange Online) account. Outlook downloads every email item from the Microsoft 365 Server to local storage and generates a local Offline Storage Table (OST) file when you set up your Microsoft 365 email account. Because of this, you can view the emails even when the system is not online. Outlook, however, needs to be linked to the Microsoft 365 Server to send or receive new emails.
There are instances when Outlook is unable to start a connection with online Microsoft 365, which prevents you from sending or receiving emails. We’ll help you in resolving Outlook and Microsoft 365 connectivity issues in this post.
Common Reasons for the Connectivity Error with Microsoft 365
There are many reasons why Outlook cannot connect to Server. Some of them are mentioned below:
- A bad network or internet connection
- Defective or incompatible add-ins
- Large or inconsistent Outlook OST data file
- Issue with the firewall or antivirus software
- Incorrect account settings or outdated login credentials
- Outage of Microsoft 365 Services
- DNS problems
- Outdated Outlook
- Outlook profile corruption
Techniques to Fix ‘Outlook Cannot Connect to Server’ Error
When Outlook cannot connect to your Microsoft 365 account (or Exchange Online), it can be caused by several factors ranging from connectivity issues to settings misconfigurations. Here’s a step-by-step guide to troubleshoot and resolve the Outlook cannot connect to Online Microsoft 365 issue:
#1. Check Internet Connection and Server Status
Check the Microsoft 365 Server’s status and your internet connectivity first. Verify that you can access other websites and services from your system and that Exchange Online (Microsoft 365) is operational. Follow these options:
- Restarting the router or modem is one option.
- Switch to Google DNS after updating to 8.8.8.8 and 8.8.4.4.
- Use a wired connection.
#2. Update Outlook and Windows
Make sure Windows and Microsoft Outlook are up to date to prevent connectivity and compatibility problems. To verify and install the most recent updates, take the following actions:
- Run MS Outlook and go to File >> Office Account.
- To see whether there are any updates available, click Update Options > Update Now.
- If there are any updates available, download and install them by following the on-screen directions.
Note: The administrator may occasionally disable the Update Now option. You must download and update Outlook from Windows updates in these situations. Check and upgrade the Windows operating system.
Restart Outlook after the update. Verify whether Outlook and Microsoft 365 can connect. Use the following fix if Outlook is still unable to connect to Microsoft 365.
#3. Check Account Settings
When your internet connection is working well, verify your login details and account settings in Microsoft Outlook. If your login credentials have expired, it can lead to connectivity problems with your Microsoft 365 account. You can set a new password and update it in MS Outlook. To follow the steps:
- Go to File >> Account Settings >> Account Settings in Microsoft Outlook.
- Choose the account that you need to update the password and tap the Change button.
- Now, update your password and press Next > Finish.
- Restart Outlook
#4. Check Firewall/Antivirus Settings
Outlook processes, files, and services may clash with firewall and antivirus software, which could interfere with and disrupt the connection between Outlook and Microsoft 365 Server. The following steps can help you overcome and resolve this:
Turn off your antivirus and firewall software for the time being.
Verify that Outlook is compatible with Microsoft 365 or Exchange Online.
If the problem with the connection has been fixed, change the firewall settings and make Outlook an exception in the program settings. Outlook and the Microsoft 365 Server will be able to communicate more easily as a result.
See the official documentation of your specific firewall or antivirus program for further information on how to add exceptions and adjust them.
#5. Use the Microsoft Diagnostic Tool
Utilise Microsoft Diagnostic Tool to find and fix the connectivity problems between the Windows Outlook and Microsoft 365 server. The Diagnostic Tool runs multiple automated checks to find the issues and offers solutions to fix them.
Moreover, users need administrator access. If you don’t have one, you can ask your IT support to help you resolve the problems. In case you can’t arrange administrator access, then follow the next solutions.
#6. Eliminate Defective Add-ins
Outlook’s functionality and features may also be hampered by defective or incompatible add-ins. To fix the Outlook connectivity issue with Microsoft 365, it is crucial to identify and remove any problematic add-ins that may be installed in Outlook. These are the steps:
- Exist Outlook program.
- Tap Windows + R, type Outlook.exe/safe, and click the Enter Key. Outlook is now open in safe mode.
- Select File > Options.
- Choose Add-ins and Click the Go button.
- After unchecking every add-in, click OK. This will make the add-ins inoperable.
- After turning off the add-ins, open Outlook as usual.
Verify that Microsoft 365 and Outlook can connect and interact. Finding and removing the problematic add-in is necessary to permanently resolve the issue, even if it has been resolved. Take the following actions:
- Start Outlook as usual.
- After restarting Outlook, activate each add-in individually.
- Verify that Microsoft 365 is updating mailbox folders and that synchronization is functioning.
If, after enabling one of the add-ins, the synchronization ceases, delete it from Outlook. That is what’s creating the problem.
The Concluding Lines!
Issues with connectivity between Outlook and online Microsoft 365 might cause communication and workflow disruptions. The preceding solutions can be used to troubleshoot and resolve the problem. Make sure to utilize CubexSoft OST Converter to convert your OST mail items to multiple file formats such as PST, PDF, MBOX, EML, MSG, DOC, Office 365, Gmail, G Suire, etc. With a few clicks and the program, you can directly import Outlook OST files to Microsoft 365.
