I'm arranging all of my messages in Outlook and need to know if theres any limit to the number of messages that can be stored in outlook. The reason being is that in one folder I have stored over 80'000 - eighty thousand messages.

Is there a limit to the number of messages that can be stored before outlook crashes or so? I need to know this

3 Answers 3


You won't have any problems with that many emails, but be aware that if you want to backup your email, there are limitations on the exported .PST file. In some cases, if it exceeds a certain file size, you will be unable to back up your email (this has happened to me in the past).

Long story short, Outlook doesn't care how many emails you have (it just stores it in a relational database). What matters more is the size of the emails you have stored, which could become problematic when trying to back-up your data, although this may only be incompatible with older versions of Outlook. In that case, the only performance penalties you pay are the same as that of a database.


There is not a limit on the number of emails you can store in a .PST however there is a size limit as well as a practical size limit. For starters Outlook 03/07 can have a maximum of 20 gigs in a PST and Outlook 2010 allow up to 50 gigs, source. I can not stress enough that for Outlook 03/07 you not let your PST go over 2 gigs. It may work fine for some people but in my experience the majority will see major issues over time, particularly if you are moving it from computer to computer. The problems are a mixture too, sometimes outlook will fail to start, sometime it’ll stop sending and receiving, sometimes it will randomly delete mail, other times the entire file can get corrupted. The best part is all of this is entirely random. We went through hell at my company before implementing email archive because users would consistently build pst that were 2-10 gigs with their archived mail. I would definitely suggest breaking it into multiple PST's, for example 06-07 and 08-09 instead of one giant pst. Of course if you are lucky enough to fit 80,000 emails in under 2 gigs you should be fine, but unless they are mostly plain text I can't see this happening.


We've got a user with over 300,000 messages in their inbox. Outlook doesn't crash, but it is somewhat slow opening.

If you're connected to an exchange server your admin might ask you to archive messages over a certain point. Our old exchange server would not deliver mail for around 2 mins when the 300k user connected in the morning. We got a new server, but for many businesses/users this would not be an option.

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