Backup fails with an error like:
"MAPI_E_NETWORK_ERROR" and "MBXBackup Fatal: Failed to Configure Message Service. Networking error"

Steps to Diagnose:

First check VSS from the command line interface of the server by typing the following command:
VSSadmin list writers
If you get an empty list, it is a different problem, please troubleshoot your VSS writer issues.
(NOTE: VSS must be DISABLED for Mailbox Level Backups)
Also check: -which indicates that MAPI needs to be updated.

Next, check the Application Logs on the server and look for a message similar to this:

"Information 5/18/2011 4:00:00 AM MSExchangeIS Public Store General 1074136261
The database "First Storage Group\Public Folder Store (SEL-BES)" has 0 megabytes of free space after online defragmentation has terminated."

This means the Public Store is out of space.

Next right click on the client and select client properties. Click on the Diagnostics tab and run the command "systeminfo" without the quotes. This will return information about the exchange server. Make note of the host name of the system, then run the command "ping hostname" where hostname is the information gathered from the previous command, and without the quotes. This should return an IP address.
If the IP address it returns is IPv4 (ex then there is no issue. If it returns an IPv6 address (ex fe80::227:eff:fe23:e25) then follow the instructions below to disable IPv6.

If possible, clear space from the Public Store.


Here are instructions on how to increase the space available for the store:

Please carefully consider these instructions.
If you choose to use the instructions, please be cautious with every step.
If the store is made too large, it can also cause problems.
16GB is the default and 75GB is the max.

1) Install Exchange 2003 Service Pack 2. This is essential! (Or make sure your Exchange Server is on the latest update available if not 2003)
2) Launch regedit
3) Navigate to HKLM/System/CurrentControlSet/Services/MSExchangeIS/
4) Under the server name there will be two folders, one called 'private', the other 'public'. Both names are followed by a long string of alphanumerics.
5) Highlight the private one.
6) Right-click it and choose NEW - > DWORD VALUE
7) Call it 'Database Size Limit in Gb' without the quotes. This is case sensitive and you must get it absolutely spot on or it will not work.
8) Double-click this new value, change the type to 'decimal' and give it any number up to 75. This is the size in Gb that you want it to be.
9) Repeat steps 6 to 8 for the public entry.
10) Restart the Exchange Information Store Service. </div>
If the issue is with IPv6 follow these instructions:
  • This only applies if the Exchange server host is not also a domain controller.
1) First open up control panel and open the network connections page.
2) Right click the network connection and select properties.
3) Uncheck IPv6 from the list of protocols used for this connection.
4) Repeat on any other network connection.
After disabling IPv6 on the connections you will need to modify the system's hosts file to exclude the IPv6 address.

1) Notepad > Run as Administrator
2) File > Open > "C:\Windows\System32\drivers\etc\" > [All Files] > "hosts" > Open

3) Comment out the line "::1 localhost"
4) Add the following two lines:


An example might look like: localhost #::1 localhost exchange-server

5) Save the file and close it.


Once this is done you should be able to run the ping command from the diagnostics page as above and it should return the IPv4 address for the local host of

*[AES]: Advanced Encryption Standard *[AESs]: Advanced Encryption Standards *[API]: application programming interface *[APIs]: application programming interfaces *[AWS]: Amazon Web Services *[AWSs]: Amazon Web Servicess *[BMR]: BareMetal Restore *[BMRs]: BareMetal Restores *[CAB]: Cloud Application Backup *[CABs]: Cloud Application Backups *[CB]: Cloud Backup *[CBs]: Cloud Backups *[CBT]: Changed Block Tracking *[CBTs]: Changed Block Trackings *[CFA]: cloud failover appliance *[CFAs]: cloud failover appliances *[CIFS]: Common Internet File System *[CIFSs]: Common Internet File Systems *[DC]: data center *[DCs]: data centers *[DDFS]: deduplication file system *[DDFSs]: deduplication file systems *[DDFS-AR]: DDFS-assisted replication *[DDFS-ARs]: DDFS-assisted replications *[DPS]: Data Protection Server *[DPSs]: Data Protection Servers *[DR]: disaster recovery *[DRs]: disaster recoverys *[DRaaS]: Disaster Recovery as a Service *[DRaaSs]: Disaster Recovery as a Services *[EULA]: end-user license agreement *[EULAs]: end-user license agreements *[GCP]: Google Cloud Platform *[GCPs]: Google Cloud Platforms *[ICAB]: Infrascale Cloud Application Backup *[ICABs]: Infrascale Cloud Application Backups *[ICB]: Infrascale Cloud Backup *[ICBs]: Infrascale Cloud Backups *[ICMP]: Internet Control Message Protocol *[ICMPs]: Internet Control Message Protocols *[IDR]: Infrascale Disaster Recovery *[IDRs]: Infrascale Disaster Recoverys *[IPMI]: Intelligent Platform Management Interface *[IPMIs]: Intelligent Platform Management Interfaces *[JVM]: Java virtual machine *[JVMs]: Java virtual machines *[LVM]: logical volume management *[LVMs]: logical volume managements *[MFA]: multi-factor authentication *[MFAs]: multi-factor authentications *[MSP]: managed services provider *[MSPs]: managed services providers *[N/A]: Not applicable *[N/As]: Not applicables *[NAS]: network-attached storage *[NASs]: network-attached storages *[NAT]: network address translation *[NATs]: network address translations *[NFS]: Network File System *[NFSs]: Network File Systems *[NIC]: network interface controller *[NICs]: network interface controllers *[NTP]: Network Time Protocol *[NTPs]: Network Time Protocols *[NTPD]: Network Time Protocol Daemon *[NTPDs]: Network Time Protocol Daemons *[OBRM]: Online Backup and Recovery Manager *[OBRMs]: Online Backup and Recovery Managers *[ODX]: Offloaded Data Transfer *[ODXs]: Offloaded Data Transfers *[PBKDF2]: Password-Based Key Derivation Function 2 *[PBKDF2s]: Password-Based Key Derivation Function 2s *[POSIX]: Portable Operating System Interface for Unix *[POSIXs]: Portable Operating System Interface for Unixs *[RAID]: Redundant Array of Independent Disks *[RAIDs]: Redundant Array of Independent Diskss *[RCT]: resilient change tracking *[RCTs]: resilient change trackings *[ROM]: read-only memory *[ROMs]: read-only memorys *[SDK]: software development kit *[SDKs]: software development kits *[SMB]: Server Message Block *[SMBs]: Server Message Blocks *[SMTP]: Simple Mail Transfer Protocol *[SMTPs]: Simple Mail Transfer Protocols *[SNMP]: Simple Network Management Protocol *[SNMPs]: Simple Network Management Protocols *[UCAR]: unique content addressable repository *[UCARs]: unique content addressable repositorys *[UDP]: User Datagram Protocol *[UDPs]: User Datagram Protocols *[UEFI]: Unified Extensible Firmware Interface *[UEFIs]: Unified Extensible Firmware Interfaces *[UNC]: Universal Naming Convention *[UNCs]: Universal Naming Conventions *[UPS]: uninterruptable power supply *[UPSs]: uninterruptable power supplys *[vCFA]: virtual cloud failover appliance *[vCFAs]: virtual cloud failover appliances *[vCPU]: virtual central processing unit *[vCPUs]: virtual central processing units *[vNIC]: virtual network interface controller *[vNICs]: virtual network interface controllers *[VM]: virtual machine *[VMs]: virtual machines *[VNC]: Virtual Network Computing *[VNCs]: Virtual Network Computings *[VPN]: virtual private network *[VPNs]: virtual private networks *[VSS]: Volume Shadow Copy Service *[VSSs]: Volume Shadow Copy Services