Event ID - 1016

Event Id1016
SourceMSExchangeIS Mailbox
DescriptionNT User NT AUTHORITY\SYSTEM logged on to <system mailbox>, and is not the primary Windows NT account on this mailbox.
Event InformationAccording to Microsoft:
You may see the preceding events even though the information store service starts. You need to mount the databases:
1. Start Exchange System Manager.
2. Expand Servers, expand Servername, and then expand First Storage Group.
3. Right-click the Mailbox Store, and then click Mount Store.
4. Right-click Public Folder Store, and then click Mount Store.
Reference LinksEvent IDs When Starting the Information Store with Blank Databases

Catch threats immediately

We work side-by-side with you to rapidly detect cyberthreats
and thwart attacks before they cause damage.

See what we caught

Did this information help you to resolve the problem?

Yes: My problem was resolved.
No: The information was not helpful / Partially helpful.