"Deep Exchange 2013"19 message throttling

In this chapter, let's talk about the QoS settings for messages in exchange, which are usually not covered in most scenarios, because mail middleware (sending a large number of promotional emails or reports) is used in scenarios where you need to send messages in bulk. But once we hit it, we need to know where to start to adjust the settings. No, it's very well written on TechNet, and we're doing a summary and handling here.

In the face of high-volume mail traffic, how to ensure that mail flow processing orderly, to avoid causing mail blocking, while protecting the Exchange server to prevent its overuse, this is a noteworthy issue. Exchange 2013 introduces a "message throttling" set of algorithms to prevent clients from inadvertently or intentionally draining system resources on the Exchange server. Of course, the message limit setting value is for SMTP mail flow through the Exchange 2013 transport system.

The message throttling algorithm in Exchange2013 is more complex, based on the QoS algorithm introduced in Exchange SP1, which calculates the average delivery cost of mail messages by message size, number of recipients, and frequency of transmission. Three values are high then the average delivery cost is also high, where the "high" refers to more than 500 recipients or a volume greater than 1MB of mail. The throttling service for Exchange monitors these costs and sets an expected cost value for each user, and once the user exceeds the expected value, his message is placed in a low priority and takes more time to pass. (When you send a message, the priority here overrides any user-manually-set priority.) The throttling service for Exchange also summarizes the average latency of RPC connections and the number of requests per second at the mailbox database level to obtain a quantifiable health value that reflects the current load situation of a database. This value ultimately affects the expected cost of all users in this database.

Here is still more general, and are relatively uncontrolled exchange within the original rational things, if you want to learn more about this paragraph, please refer to: Mail sms and mail flow restrictions https://technet.microsoft.com/zh-cn/library /bb232205 (v=exchg.150). Aspx#cost

You can adjust the message restriction options in the following settings:

1. Transport Service : Set-transportservice with set-mailboxtransportservice command. In general, administrators only need to restrict external traffic, or restrict settings for one or several specially busy transport servers.

2. Receive connector : Set-receiveconnector command, again, note that this setting is used to restrict incoming mail traffic from outside your organization.

3. Send connector : set-sendconnector command

Note that the default Exchange throttling settings generally meet the needs of most scenarios, unless some transport servers have been exposed on performance monitoring and the edge servers have been in a busy load state. For example, there is a lot of queue accumulation during peak hours, and the queue is still not reduced after the peak hours. This is likely to reflect that the server processing power has not been able to keep up, or some other conditions caused by these conditions you can adjust the parameters to solve. The following table summarizes the different parameters that you can use to control transport restrictions.

Command set	Parameters	Role
Set-transportservice or Set-mailboxtransportservice	Maxconcurrentmailboxdeliveries	This parameter specifies the maximum number of delivery threads that the transport service can open when a message is delivered to a mailbox. The default value is 20 and the parameter range is 1-256. In particular, Microsoft said: If it is not necessary, please modify this value with customer support suggestions.
Set-transportservice or Set-mailboxtransportservice	Maxconcurrentmailboxsubmissions	This parameter specifies the maximum number of submission threads that the transport service can open when sending messages from a mailbox. The default is 20 and the parameter range is 1-256.
Set-transportservice	Maxconnectionrateperminute	This parameter specifies the maximum rate at which inbound connections are allowed to open connections to the transport service. The default value is 1200.
set-transportservice or Transport server Properties	maxoutboundconnections
Set-transportservice or Transport server Properties	Maxperdomainoutboundconnections	This parameter specifies the maximum number of concurrent connections for any one domain. If the input value is unlimited, the number of outbound connections per domain is not limited. Default is 20 You can also configure this value by using the EAC in Server > Server > Properties > Transport Restrictions > Outbound connection restrictions.
Set-transportservice	Pickupdirectorymaxmessagesperminute	This parameter specifies the maximum number of messages processed per minute by the pickup directory and the replay directory. Each directory is able to process the message file independently at the rate specified by this parameter. Default is 100
set-receiveconnector	Span style= "FONT-SIZE:14PX;" >connectioninactivitytimeout
Set-receiveconnector	ConnectionTimeout	This parameter specifies the maximum amount of time that an SMTP connection to the source messaging server can remain open, even if the source mail delivery server is transmitting data. The value of this parameter must be greater than the value specified by the Connectioninactivitytimeout parameter. Default: Transport service on a mailbox server 10 minutes The front end transport service on the Client Access server is 10 minutes. On the Edge Transport server for 5 minutes.
Set-receiveconnector	Maxinboundconnection	This parameter specifies the maximum number of inbound SMTP connections that this receive connector allows to establish at the same time. Default is 5000
set-receiveconnector	Span style= "FONT-SIZE:14PX;" >maxinboundconnectionpercentagepersource	default: 100% The default Receive connector in the transport service on a mailbox server is 2% in the transport server on the mailbox server, and other receive connectors in the front end transport service on the Client Access server.
Set-receiveconnector	Maxinboundconnectionpersource	This parameter specifies the maximum number of SMTP connections that the Receive connector allows to be established from a single source mail delivery server at the same time. Default value: Unlimited The default Receive connector in the transport service on a mailbox server (limited by maxinboundconnection) 20 The transport server on the mailbox server, the other receive connectors in the front end transport service on the Client Access server.
Set-receiveconnector	Maxprotocolerrors	This parameter specifies the maximum number of SMTP protocol errors that the receive connector allows to occur before the receive connector disconnects from the source mail delivery server. The default is 5 times.
Set-receiveconnector	Tarpitinterval	This parameter specifies the delay used in the ease-of-delivery technique. The ease-of-delivery technique is a method of artificially delaying an SMTP response for a specific SMTP communication pattern that indicates the presence of an account-gathering attack or other unwelcome message. The Account collection attack attempts to collect valid e-mail addresses from a specific organization as a target for commercial spam. The delay specified by the Tarpitinterval parameter applies only to anonymous connections. The default is 5 seconds.
Set-sendconnector	Connectioninactivitytimeout	This parameter specifies the maximum amount of time that an open SMTP connection to the target messaging server can remain idle before the connection is closed. Default is 10 minutes

Finally, in Exchange 2013, each mailbox has a throttlingpolicy setting. The default value for this setting is empty ($null). You can create a throttling policy, and then use the Throttlingpolicy parameter on the Set-mailbox cmdlet to configure throttling policies for the user mailboxes that you want to apply. It is generally not recommended to make any changes to the throttling policy unless you are very concerned about the resource usage of these users for the following features, where the settings are primarily the number of activities that the user can perform on the Exchange through a specific connection or at a specific time, which affects the user's expected cost value:

• · Exchange ActiveSync

• · Exchange Web Service (Exchange Web Services)

• · Outlook Web App

• · Unified Messaging

• · IMAP4

• · POP3

• · Outlook Client Connection (MAPI or RPC connection)

• · Mail Flow settings

• · PowerShell command

• · CPU usage

The main command involved is Get/remove/new/set-throttlingpolicy, and then bind to the user's mailbox.

OK, email restrictions talk about it here, next chapter Let's talk about another exchange's self-protection against peak traffic-back pressure.

This article is from the "Castamere Rainy season" blog, be sure to keep this source http://sodaxu.blog.51cto.com/8850288/1684075

Deep Exchange 2013"19 Message restrictions