MaxMessageSize

HKLM\SOFTWARE\Microsoft\MSMQ\Parameters

Data type Range Default value
REG_DWORD 0x0 - 0xFFFFFFFF bytes 0x400000 (4 MB)

Description

Determines the maximum size of the message file. Because messages must fit in the file, the value of this entry also limits the size of messages sent and received by Message Queuing.

When Message Queuing starts, it restores all persistent messages in message files. If Message Queuing finds a message file larger than the value of this entry, it might not operate correctly. Also, when Message Queuing encounters messages larger than this value, it blocks all further transports from the sending computer. To restore communication, you must set the value of this entry greater than or equal to the size of the message that exceeded this value, and then restart Message Queuing.

If you increase this value, you might be able to transmit larger messages between applications on the same computer. However, because this entry affects both incoming and outgoing messages, in order to send a larger message to other computers running Message Queuing, you must increase this value on all participating systems. If any system has a lower value, it might block all further transports from computers sending larger messages.

Activation method

Message Queuing checks this entry only at startup. If you change the value of this entry, you must restart Message Queuing to make the change effective.

Note Image Note

This entry affects Message Queuing only. It does not change characteristics of the network or network programs that might limit the size of messages.

Caution Image Caution

Do not change the value of this entry. Increasing this value might prevent you from sending messages larger than 4 MB. Decreasing this value might block all further transports between Message Queuing computers.