Applies to: Exchange Server 2013, Exchange Online
Topic Last Modified: 2012-11-28
You can use the EAC or the Shell to manage POP3 connection limits for your organization.
When you specify connection limits for POP3, you can select connection limits for the server, an IP address, or a specific user.
For additional information related to POP3, see POP3 and IMAP4.
What do you need to know before you begin?
- Estimated time to complete: 5 minutes.
- You need to be assigned permissions before you can perform this
procedure or procedures. To see what permissions you need, see the
"POP3 settings" entry in the Clients and Mobile
Devices Permissions topic.
- For information about keyboard shortcuts that may apply to the
procedures in this topic, see Keyboard Shortcuts in
the Exchange Admin Center.
 Tip: |
|---|
| Having problems? Ask for help in the Exchange forums. Visit the forums at: Exchange Server, Exchange Online, or Exchange Online Protection. |
What do you want to do?
Use the EMC to set POP3 connection limits for a server, an IP address, or a user
- In the EAC, navigate to Servers >
Servers.
- In the list of servers, select the Client Access server, and
then click Edit
.
- On the server properties page, click POP3.
- Scroll down and click More options.
- Under Connection limits, use the following settings:
- Maximum connections Specifies the total
number of connections the specified server will accept. This
includes authenticated and unauthenticated connections. The default
value is 2,147,483,647. The possible values are from 1 through
2,147,483,647.
- Maximum connections from a single IP
address Specifies the number of connections
that the server will accept from a single IP address. The default
value is 2,147,483,647. The possible values are from 1 through
2,147,483,647.
- Maximum connections from a single
user Specifies the maximum number of
connections that the server will accept from a particular user. The
default value is 16. The possible values are from 1 through
2,147,483,647.
- Maximum command size (bytes) specifies
the maximum size of a single command. The default size is 512. The
possible values are from 40 through 1,024.
- Maximum connections Specifies the total
number of connections the specified server will accept. This
includes authenticated and unauthenticated connections. The default
value is 2,147,483,647. The possible values are from 1 through
2,147,483,647.
- Click Apply, and then click OK to save your
changes.
After you set connection limits, you must restart the POP3 services. For information about how to restart the POP3 services, see Start and Stop the POP3 Services.
Use the Shell to set POP3 connection limits for a server, an IP address, or a user
This example sets the connection limit for a server.
 Copy Code |
|
|---|---|
Set-PopSettings -Identity CAS01 -MaxConnections Value |
|
This example sets the connection limit for an IP address.
| Copy Code |
|
|---|---|
Set-PopSettings -Identity CAS01 -MaxConnectionsFromSingleIP Value |
|
This example sets the connection limit for a user.
| Copy Code |
|
|---|---|
Set-PopSettings -MaxConnectionsPerUser Value |
|
This example sets the maximum command size.
| Copy Code |
|
|---|---|
Set-PopSettings -MaxCommandSize Value |
|
After you set connection limits, you must restart the POP3 services. For information about how to restart the POP3 services, see Start and Stop the POP3 Services.
For more information about syntax and parameters, see Set-PopSettings.
How do you know this worked?
To verify that you’ve successfully set connection limits, do one of the following:
- In the EAC, navigate to Servers >
Servers.
- In the list of servers, select the Client Access server, and
then click Edit .
- On the server properties page, click POP3.
- Scroll down and click More options.
- Under Connection limits, verify the connection settings
are correct.
Or
- Run the following command in the Shell.
Copy CodeGet-PopSettings | format-list
- Verify the connection settings are correct.
For more information
After you set POP3 connection limits for a server, an IP address, or a user, you may also want to: