Exchange Online Frequently Asked Questions

If you have a question that isn't answered here, please email us at

Starting in the Summer of 2012, IITS began moving Faculty/Staff email to Microsoft's Exchange Online. Users will be notified in advance of being moved to the new system. Please read below for more details.

Will my email address change?

No, your CSUSM email address will stay the same.

Will Outlook go away with Exchange Online?

No, you will still use your local email client (e.g. Outlook 2007, Outlook 2010, Outlook 2011 for Mac, or Entourage 2008 for Mac) for your day-to-day work.

Are we changing email services?

No, IITS is still providing the campus the same Microsoft Exchange email service that we've offered in the past, but updated to Microsoft's latest version of Exchange (i.e. Exchange Online/Exchange 2010).

Exchange Online provides rich, familiar, and more secure access to email, calendar, contacts, and tasks across PCs, the web, and mobile devices. It delivers the robust capabilities of Microsoft Exchange Server as a cloud-based service.

Will I get to keep all of my current email, calendar, contacts, and/or tasks?

Yes, all your email, calendar, contacts, and tasks will be migrated.

Are the file size and delivery limits changing?

Mailbox Size Limit

Each mailbox will have a mailbox size limit of 25GB. This is a hard limit per Microsoft.

Attachment Size Limit

There is a 10MB hard limit for attachments.

Total message size limit, including attachments

  • There is a 25MB hard limit for total message size, including attachments, per Microsoft.
    • Messages larger than this limit will not be delivered, and the sender will receive a Non-Delivery Report (NDR).
  • There is a 30 messages per minute send limit.
    • If a user submits messages at a faster rate, Exchange Online will deliver the messages but will queue the messages at the server and throttle the rate of delivery.

Recipient Limit

Each mailbox can send emails to a maximum of 1,500 recipients per day. An email can be addressed to a maximum of 500 recipients per email.

Note: A personal distribution group counts each recipient separately.

Distribution List Limit

There is a 5,000 member hard limit per Microsoft.

Contacts synchronization

Contacts will be able to be accessed through Outlook, Exchange Online (the new Outlook Web Access/Copilot) or by a mobile device(s).

How will I access my .pst files?

.pst emails will be moved into the mailbox and will be able to be accessed through Outlook, Exchange Online, or by a mobile device(s).

How do I access my mailbox from the web?

Updated Exchange Online (the new Outlook WebAccess/Copilot) interface. - More features, with a similar look to Outlook 2010.

What about Public Folders?

Public Folders are no longer available.

If you're looking for the old "Announcements" public folder, please email Linda Collins ( to be added to the new "CSUSM Bulletin Board."

When will I be migrated to Exchange Online?

The timeframe for migration is Summer 2012 through October 2013. You will be contacted via email by IITS in advance of your migration, so you are informed of your migration date.