Migrate IMAP Calendar to Office 365 in Just a Few Steps
-
Written By
Aradhya Jain -
Approved By
Shivam Rathore -
Updated on
November 20th, 2025 - Read Time
6 minutes
User Query: I’ve been using an IMAP email service for a long time, and all my important meetings and events are saved in its calendar. My company recently shifted to Office 365, and now I need to transfer my calendar there. How can I migrate IMAP Calendar to Office 365 without losing dates or reminders?
Summary: Many users face this situation when their organization transfers from an old IMAP-based email service to Office 365. All their meetings, reminders, and upcoming events remain stored in the old calendar, making the shift feel complicated. The good news is that you can easily migrate Calendar from IMAP to Office 365 without losing any important dates. In this guide, we’ll discuss the manual method and a professional DRS Softech IMAP Backup Tool for a hassle-free process.
Why Do Users Need to Import IMAP Calendar to Office 365?
- Office 365 offers better calendar management and sharing.
- Events automatically sync across Windows, Mac, Android, and iPhone.
- Safe cloud storage prevents accidental loss of meetings and schedules.
- Additionally, ideal for business teams needing shared calendars and meeting invites.
Can You Manually Transfer IMAP Calendar to Office 365?
Yes, this method is simple, but it may not work for large calendars or multiple accounts. Also, the process requires two steps:
Step 01: Exporting your calendar from IMAP in ICS format
Most IMAP webmail services (Roundcube, Horde, cPanel Webmail, SquirrelMail, etc.) provide an export option. Here is how you can perform it:
- Firstly, sign in to your IMAP webmail.
- After that, open the Calendar tab.
- Now, click Export, Download, or Save Calendar.
- Then, save the calendar in .ics format.
- Your ICS file contains all scheduled events and reminders.
Step 02: Import the Calendar into Office 365
- Next, log in to Office 365.
- Click the Calendar icon.
- Choose Add Calendar on the left panel.
- Further, select Upload from File.
- After that, choose the downloaded ICS file.
- Select the Office 365 calendar where events should be saved.
- In the end, click Import to complete the migration process.
Limitations: Manually Move IMAP Calendar to Office 365 Account
- It requires exporting each calendar separately.
- Some IMAP servers don’t support full calendar exporting.
- Large ICS files may fail to upload to Office 365.
- Recurring events might not import correctly.
- Moreover, not recommended for companies or multiple users.
Effective Way to Migrate IMAP Calendar to Office 365
The DRS Softech IMAP Email Backup Tool is a quick and hassle-free solution to migrate multiple IMAP emails at once. Offer several advanced features, like Preview, Remove Duplicates, Date Filter, and more. Designed with a user-friendly interface, every user can easily perform it without needing any technical skills. Maintains the original data confidentiality, integrity, and accessibility during the migration. Additionally, you can complete the migrate from IMAP to Office 365 and other email clients.
Simple Steps to Migrate IMAP Calendar to Office 365
- Download and install the DRS Softech IMAP Backup Tool.
- Enter your IMAP credentials, such as ID & Password, to Sign In.
- Then, you can preview and select the IMAP emails to import.
- Choose IMAP (Office 365 Support) as the Saving Format from the list.
- Now, write your Office 365 details to Sign In.
- Lastly, apply advanced features/filters and click Convert.
One-Time Service Available
If you don’t want to handle the migration yourself, you can choose a one-time migration service. A professional team transfers your IMAP calendar to Office 365 for you, ensuring every event, reminder, and meeting moves safely without errors. You only pay once, and the entire process is handled securely.
Real-Life Scenario:
Imagine a small US-based marketing company switching from an old IMAP email system to Office 365. Their project manager, Emily, has years of client meetings, campaign deadlines, and team schedules saved in her IMAP calendar. She can’t risk missing any dates during the transition. Instead of doing it manually, she uses a secure one-time service that moves her entire calendar to Office 365 in a few minutes.
Conclusion
In this technical blog post, we explored several methods to migrate IMAP calendar to Office 365. The manual method is free to use and is only used to migrate a small number of IMAP emails. But, this method has several limitations that make unreliable choice for many users. So, it’s highly suggested to use the professional tool. It supports bulk migration with several advanced features. A free version of this tool is available to evaluate its features and functions. Apart from that, this tool is highly compatible with all Windows versions.
Frequently Asked Questions
Ans: Office 365 allows you to upload an ICS calendar file manually, but this works only for basic or small calendars. If you have multiple users, large calendars, or recurring events, using a professional tool like the DRS Softech IMAP Backup Tool is a safer and smoother method.
Ans: Yes. With manual import, you can export only the calendar you choose. If you use the DRS IMAP Backup Tool, you can also select specific folders or apply filters to move only the events you want.
Ans: This usually happens if the ICS file didn’t export completely or if some recurring events were not supported during import. Try exporting the calendar again, or use a tool that supports full event mapping to restore all missing items.
Ans: The manual method doesn’t support resume. However, the DRS IMAP Backup Tool allows you to restart or continue the migration from where it stopped. This saves time and prevents duplicate entries.
Ans: When using the manual method, the structure may change based on how the ICS file is imported. To keep the same hierarchy, it’s better to use a tool that maintains the original layout during the migration.
