Topic Last Modified: 2007-01-24
The following two message size limit settings exist:
- Limit message size to This is a
preferred message limit for the virtual server. This is what the
SMTP service will advertise as the maximum message size that the
Simple Mail Transfer Protocol (SMTP) virtual server will accept. If
a mail client sends a message that exceeds the limit, the client
receives an error. If a remote server supports EHLO, it will detect
the advertised maximum message size value when it connects to the
SMTP virtual server and won't try to deliver a message that exceeds
the limit. Instead it will send a non-delivery report (NDR) to the
sender of the message. A remote server that doesn't support EHLO
will try to send a message that exceeds the size limit, but will
send an NDR to the sender when the message doesn't go through.
- Limit session size to This is the
maximum amount of data accepted during the total connection. This
is the sum of all messages sent during the connection (applying to
the message body only).
To set message size limits
In Microsoft Management Console, select the SMTP virtual server, and then click Properties on the Action menu.
On the Messages tab, select Limit message size to (KB), and then type a value (in kilobytes) for the maximum size of a message. The default is 2,048 KB. The minimum value is 1 KB.
On the Messages tab, select Limit session size to (KB), and then type a value to indicate the maximum total size (in kilobytes) of all messages in a specific connection. This number will always be larger than the maximum message size and should be set carefully because the connecting message transfer agent (MTA) is likely to resubmit the message repeatedly. The default size is 10,240 KB. This value should be greater than or equal to the value entered for Limit message size to (KB).