How to increase Microsoft outlook desktop PST & OST file size limit up to 100 GB (Maximum)||2023

Web page link:

Microsoft E1, E3, and E5 have 100 GB mailboxes.
But the Outlook desktop version PST/OST file size limit is 50 GB.
Extend up to 100 GB.

Registry path:
Outlook 2016 / Outlook 2019 / Microsoft 365 HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\PST

WarnLargeFileSize

Don’t set this higher than 4090445042 (decimal) or f3cf3cf2 (hexadecimal)
MaxLargeFileSize

Don’t set this higher than 4294967295 (decimal) or ffffffff (hexadecimal)

[shamirkhan]

Great tip. I needed this today and its working now after following your instructions. Many Thanks.

[tUBEROCKErPriyankar]

Your video saved my life 🥺🥺🤓🤓👏👏👏❤️❤️❤️Thank you so much for this.

[ghfgg]

Good job done. That's a great video.

[joseph.bkazmi]

this worked beautifully thank you! If you can also produce a video tutorial on how to maintain and keep file size under 100 GB that would be very helpful. With my line of work, i have a feeling this extra 50 GB of space will be used up very quickly.

[Rvd]

Really it was so good 👍👍 great very helpful ❤❤. आपको बहुत बहुत आभार धन्यवाद, ये बहुत अच्छे से समझ आया, मेरी pst max हो गई थी, कुछ भी नहीं दे रही थी लेकिन आपके ज्ञान के कारण मेरा काम आसानी से हो गया है आपको बहुत बहुत आभार धन्यवाद ❤❤

[augustusamul]

thank you, this is great. It worked like a charm! (Not sure if this is related but when I try to send emails, it stays in my Outbox unless I restart Outlook again which will then send after)

[georgetsilikis]

You are the best my man. Hail to INDIA

[KrissofallTrades]

When I try to do this on Outlook desktop running Office 365, I keep on getting ""errors have been detected in the file" and it points to the OST. I deleted the mailbox and recreated it and error comes back after a few hours. Has anyone else had that issue? OST file size is 53GB.

[kousiqrafi]

There's no PST file option in my desktop.. :(

[Xxx-xmso]

"Does it work with Outlook in the Office 365 package as well?"

[sgtpepper]

This solution didnot work for me, my mailbox remains at 49.5Gb, not sure what I did wrong

[Methuselah]

Hi, very great video, but how can i confirm that it worked even my .ost file is not yet near at 50GB? Thanks!

[chandrapilli]

With no restart, it functions for me.

[raymondha]

thanks. but this one Microsoft dont have the supporting kb

[Technicalsupport-fnyf]

It's works in GWSMO (gmail syncing issue) ?

[TrubbleMaker]

I'm running Office 2019 (perpetual licence).

I have a Microsoft 365 Business basic plan for Outlook.

I'm on the verge of hitting my limit of 50Gb (49.6Gb ish). I read somewhere that I can upgrade the mailbox size to 100Gb by subscribing to a Plan 2 but I have not been able to find the procedure anywhere.

A Microsoft agent told me that I have to upgrade to Microsoft 365 Apps for Business and I'm happy to do that, but my questions are:

a) Is that the BEST solution (I was hoping to be able to just tick a box somewhere so that the mailbox size is automatically increased to 100Gb at Microsoft's end, and they charge me accordingly); or
b) If I go ahead with the Microsoft 365 Apps for Business plan, do I need to download and run the Microsoft 365 applications, or can I just keep using the Outlook 2019?

Will the above instructions solve my problem?