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 Frank_Lee,
here are some insights regarding the issues you raised:
- Outlook Warning Window: The warning you received is a result of your Outlook data file (`.ost`) reaching its maximum size. To resolve this, consider permanently deleting unnecessary items to reduce the file size.
- Mailbox Storage Limit: Outlook accounts allow up to 100GB of storage per mailbox. If your mailbox is nearing its limit, Outlook will notify you via emails and in-app messages. You can use Mailbox Cleanup, a one-stop-clean-up tool you can use to trim the size of your mailbox.
Manage my mailbox size - Microsoft Support
Mailbox storage limits in Outlook - Microsoft Support
- OST File Limit: The maximum OST file size depends on your Outlook version. Versions 2010 and later support up to 50GB, while earlier versions support up to 20GB.
You can adjust the maximum size through registry entries.
How to configure the size limit for both (.pst) and (.ost) files in Outlook - Microsoft Support
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)
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_LeeHi 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)
