Copying many items in Outlook – troubleshooting

Copying or moving many items in Outlook isn’t easy – here’s how to avoid Outlook’s deficiencies.

For as long as Outlook has existed, there have been problems when you copy or move many items around. Here are some suggestions from years of experience and frustration.

When transferring many items, Outlook gets bogged down terribly. You’ll get ‘Not Responding’ messages that may or may not clear after a few minutes. It’s common to get system resources errors that seem to be related to moving many items at once.

In recent versions the copy/move command has been a little more reliable, especially for transferring an entire folder. It appears that some code was changed to transfer entire folders in segments rather than all in one hit.

The problems are more common when transferring between data stores (ie between PST or OST’s). Transferring within a single data store doesn’t seem to bother Outlook so much.

How many items is ‘many’ and might cause trouble in Outlook? That depends on the computer, version of Outlook and seemingly the relative position of the sun and moon . Outlook should be able to handle under 1,000 items without trouble but there are no guarantees. As they say in car ads “Your mileage may vary”.

Not Responding error

When moving/copying items, you may see ‘(Not Responding)’ appear in the Outlook title bar and you can’t do anything in Outlook.

Usually this fixes itself. Outlook gets consumed with itself while transferring many items but usually the ‘Not Responding’ message disappears after some time and you can continue using Outlook.

Out of Memory / System Resources errors

If you get any errors that suggest the system is out of memory or system resources – then it’s time to close down Outlook entirely and restart.

It doesn’t matter how much memory or free memory you have on your computer – once Outlook gives one of those error messages you need to restart the program.

Use menu not clipboard

You can copy then paste Outlook items using the clipboard shortcuts (Ctrl + C etc) however that appears to make things worse. The Windows clipboard grows very large and causes errors.

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We strongly suggest you copy/move items using the Outlook menu choices (right-mouse click, ribbon or menu) because that seems less resource intensive.

Copy entire folders

Outlook handles copying entire folders better than many selected items within a folder.

Whenever possible, copy an entire folder between data stores (ie PST or OST). Once in the new data store you can move the items with less angst.

It often happens that the destination Outlook folder is fixed and can’t be removed (Inbox, Calendar, Contacts etc). This happens for Exchange Server / Office 365 accounts. That means you can’t directly copy a folder over to replace one of those fixed folders.

The workaround is to copy the folder to a temporary location in the target data store. We make a ‘Temp’ Outlook folder in the destination data store then copy entire folders to be sub-folders of ‘Temp’.

Outlook - temp folder while copying items.jpg image from Copying many items in Outlook – troubleshooting at

Once you have a copy of all the items saved under ‘Temp’ you can select say, all Contacts, and move them to the regular Contacts folder. You should move the items to save space and unnecessary duplication in the new data store.

Once everything is in its new home you can remove the Temp folder and sub-folders.

Copying in segments

An alternative is copying a collection of items in smaller groups instead of all at once.

Instead of copying, say, 5,000 items copy them in groups of 1,000 at a time.

Keep a careful track on which items have been copied (maintain the same sorting order on the view) and which are left to go.


Of course, the real solution would be for Microsoft to devote a tiny slither of their enormous development resources to fixing the problems.  Outlook should be able to copy many items without causing trouble, especially between data stores.  A folder of items should be copied over another folder to merge them (just as in Explorer).  Duplicate items should be identified and the user warned (just like in Explorer). Ideally all this should happen in the background so the customer can continue working.

Bulk movements of Outlook items aren’t common but happen often enough that Microsoft should not be ignoring the issue.  As more people radically change the way they handle email (ie from a single Outlook store to a store on a server or cloud) there’s more demand for a properly working set of copy/move tools in Outlook.