Forum Discussion
Seeking Assistance: Outlook Warning, Storage, and OST File Limit
Hi Frank_Lee,
thanks for the update.This issue is specifically related to Outlook 2010 and later versions, where the default maximum size for .ost files is set at 50GB, independent of your overall mailbox storage.
Despite having a 100GB mailbox, the .ost file has its own size limit, leading to the warning message you're seeing.
To manage this situation, consider the following options:- Clear Out the Mailbox: Regularly delete unnecessary emails and attachments, and empty the "Deleted Items" folder.
- Adjust "Mail to Keep Offline" Settings: Reduce the amount of mail kept offline in the OST file.
Work offline in Outlook - Microsoft Support - Move Mail Items to Archive Folder: Move older items to an Archive folder.
Archive in Outlook for Windows - Microsoft Support
If needed, you can increase the .ost file limit beyond 50GB by adjusting registry entries.
https://support.microsoft.com/en-us/topic/how-to-configure-the-size-limit-for-both-pst-and-ost-files-in-outlook-2f13f558-d40e-9c2a-e3b6-02806fa535f4Please click Mark as Best Response & Like if my post helped you to solve your issue.
This will help others to find the correct solution easily. It also closes the item.If the post was useful in other ways, please consider giving it Like.
Kindest regards,
Leon Pavesic
(LinkedIn)
Hi LeonPavesic,
Thank you for your insights on the issues I raised. I have a follow-up question regarding the warning message I received about my Outlook data file (*.ost) reaching its maximum size. I currently have a total mailbox storage of 100GB (50GB default + 50GB from an additional plan), and I've only used up 56GB. Despite this, I'm still encountering the warning message.
Could you clarify if the warning is specifically related to the .ost file exceeding 50GB, even if the overall mailbox storage is 100GB? And is there any way to extend the .ost file limit beyond 50GB?
I appreciate your assistance.
Best regards,
Frank_Lee
Hi Frank_Lee,
thanks for the update.
This issue is specifically related to Outlook 2010 and later versions, where the default maximum size for .ost files is set at 50GB, independent of your overall mailbox storage.
Despite having a 100GB mailbox, the .ost file has its own size limit, leading to the warning message you're seeing.
To manage this situation, consider the following options:
- Clear Out the Mailbox: Regularly delete unnecessary emails and attachments, and empty the "Deleted Items" folder.
- Adjust "Mail to Keep Offline" Settings: Reduce the amount of mail kept offline in the OST file.
Work offline in Outlook - Microsoft Support - Move Mail Items to Archive Folder: Move older items to an Archive folder.
Archive in Outlook for Windows - Microsoft Support
If needed, you can increase the .ost file limit beyond 50GB by adjusting registry entries.
https://support.microsoft.com/en-us/topic/how-to-configure-the-size-limit-for-both-pst-and-ost-files-in-outlook-2f13f558-d40e-9c2a-e3b6-02806fa535f4
Please click Mark as Best Response & Like if my post helped you to solve your issue.
This will help others to find the correct solution easily. It also closes the item.
If the post was useful in other ways, please consider giving it Like.
Kindest regards,
Leon Pavesic
(LinkedIn)