Outlook - Profile Summary
An Outlook profile is a set of configuration settings that tells Outlook classic which email accounts to open, how to connect to them, and which local data files are associated with them.
Information
What an Outlook profile includes
Email accounts
A profile can include a primary account and additional accounts. These might be Microsoft 365, Exchange, Outlook.com, IMAP, or POP accounts, depending on how Outlook is being used.
Data files
Outlook profiles can use two main types of data files:
OST (.ost): Used for Microsoft 365, Exchange, Outlook.com, and other accounts. An OST is an offline synchronized copy of mailbox data, allowing users to work offline and sync changes when they reconnect.
PST (.pst): Used mainly for POP accounts and for local archives, exports, and backups. A PST stores Outlook items such as mail, calendar items, contacts, and tasks in a file on the computer.
Account and connection settings
A profile stores the settings Outlook needs to connect to mail services as well as where Outlook delivers and stores data for each account.
Outlook behavior and preferences
Some Outlook behavior is tied to the profile, such as which account or profile opens by default and which data file is used for delivery. Other settings, like many mailbox rules and some sync behavior, may depend on the mailbox or server rather than only on the local profile.
Why you might create multiple profiles
Separate work and personal mail
Multiple profiles can keep different account setups separate, which can make troubleshooting and day-to-day use simpler.
Different users on one PC
Separate profiles can give different users different Outlook setups on the same device.
Troubleshooting
Creating a new Outlook profile is a common fix for send/receive issues, startup problems, corruption, or odd behavior caused by a damaged profile.
How profiles are managed
The preferred ways to modify a profile are through Outlook’s Account Manager or the profile picker.