OST to PST software then import into new Office 365 OST file

I recommend you also consider the suite of Stellar Tools.

https://www.stellarinfo.com/outlook-pst-file-recovery.php?gclid=EAIaIQobChMIgbfw0oLt2AIVybfACh2RfAP1EAAYASAAEgKIlPD_BwE

They have tools for PST Repair and OST to PST conversion.

I have successfully used their PST Repair tools.

thx John I will take a look

Or one of these previous solutions on EE
https://www.experts-exchange.com/searchResults.jsp?searchTerms=ost+to+pst&searchSubmit=&asSubmit=true&asIgnored=true

If the OST files; you are migrating to Office 365 are healthy, then you can use Kernel Import PST to Office 365 tool which can directly migrate PST/OST files to Office 365, but the only limitation is that PST/OST file should be healthy.

As you said that there is some corruption issue in OST files, then you need to use Kernel for OST to PST converter tool. It can repair a damaged OST file, and then convert them to PST and easily exports OST data to Office 365. Visit: https://www.nucleustechnologies.com/ost-to-pst-converter.html to know more about OST to PST tool and download the demo application.

To perform the hassle free conversion of OST file to PST, I would like to refer an excellent third party solution, known as, Export OST to PST. The software is also capable to perform conversion of Unicode characters. To download the software for easy and error free recovery of OST file, go to- http://www.ostfileexporter.com

Thanks for your input & comments everyone! I  will let you know how it goes tomorrow, cheers.

You are recommended for utilizing some professional Microsoft application to Convert the OST emails to PST no successfully import into Office365. There are so many tools but we recommend for using our out and out KDETOOLS OST to PST Converter tool for superb results.

• Convert unlimited OST files to PST
• Import OST file database into Office 365
• import OST file database into Live Exchange Server
• Converts all emails, contacts, folders, attachments etc
• Save OST in PST, EML, MSG, HTML, MBOX for mac mail
• Support all version of MS Exchange and MS Outlook

Get try to free solution:
http://www.kdetools.com/ost-to-pst-converter.html

thanks I will try that one David as only one of the other suggested programs showed a few missing emails there is a big gap between Aug 17 - Dec 18 the file is not able to be opened at all so corruption appears to have got the better of it I have copies in my office which I will work on and see how we go, cheers.

Sorry this was put on hold I had written a comment but didnt save it and lost it... ok to update this is the option I am looking at going with as it showed most of the missing mail required.

MailsDaddy OST to Office 365 Migration Tool

Will post back tonight upon the result, thanks.

Dear @it_fan, I hope the solution you are trying will work for you.  :)

Hello,
I will suggest you to never go for manual procedure. As it might cause of data loss, so instead of converting OST to PST file then import PST file to Office 365 account,the best way is to choose trustworthy tool, as per my opinion SysTools OST to PST Converter would be the best option. This utility is 100% safe, secure and authentic. I would like to share a very useful blog which will describe how to import OST to Office 365 account.
For more information visit here : https://convertmyemail.blogspot.in/2016/06/how-to-import-ost-to-office-365.html
Please let me know if you need further assistance.

I have the chosen method and will adjust for points, thanks.

Thankyou everyone for your comments and suggestions, VIP Sharma's solution worked best for me on this occasion and Geeta and Praveens were a good suggestion. I did try all the other options but Mailsdaddy revealed what I was looking for first up, cheers.

Great to hear that Mailsdaddy solution worked for you :)