Email in Outlook connected with Exchange mailbox is quite safe. The usual mail storage file (PST) is replaced with a mirror of the data (OST file) saved directly on the company’s server. If anything bad happens to your computer, or the OST storage file gets corrupted - no worries, all your data is safe and sound in the central mailbox database.
However it is quite often that the company policy sets the limit to the size of your Exchange mailbox. If you preserve too many messages and reach the full capacity of the storage the server will disable sending any emails from your address.
To help this situation Outlook is fitted with the archiving feature. In short - it automatically saves all Outlook items (emails, tasks, appointments etc.) older than a set threshold to a separate PST file, stored locally on your computer. This way you can keep your Exchange mailbox small and below the company’s limit and maintain access to all your old mail as well.
Unfortunately, since the archive PST file is stored locally on your computer, it is not protected the same way as your mailbox. If the hard drive of your PC fails or the PST file is corrupted, all your archived data may be lost. A good idea is configuring the archiving function to store the PST data file directly on the company server (e.g. in a network shared folder). The drawback is that when disconnected from your company’s network you cant access the archive.