Outlook Express and Microsoft Outlook

Dear Tom W Jones

Welcome to Microsoft Community.  

Hello, Express is indeed a very old version of software, and Microsoft has stopped supporting this software.

May I ask what email you are using? You can now configure your email on your existing version of Outlook and check if it can be automatically synchronized to your email. Please note that if it is a non third-party email, use the exchange protocol. For third-party emails, the IMAP protocol needs to be configured. If automatic synchronization is possible, it is highly likely that the calendar will be synchronized over (but not 100%).

In addition, if the email has not been synchronized after configuring it, you can try exporting and importing it into Outlook email again.

Outlook Express: Move your email to Outlook.com - Microsoft Support

The IMAP file and OST file you mentioned are not the same thing.

1. IMAP: This is a mail protocol that allows you to remotely access emails from a mail server instead of downloading them locally. It is not a file format.

2. OST: This is an offline data file format used by Outlook, typically used to cache emails and data for Exchange accounts, so that they can also be accessed offline. It is not a format used for importing data.

We look forward to your reply.

Best regards ！

Yolanda - MSFT | Microsoft Community Support Specialist