Microsoft KB Archive/137105

= Microsoft Knowledge Base =

Size Limits for E-mail on The Microsoft Network
Last reviewed: October 7, 1997

Article ID: Q137105

The information in this article applies to:


 * The Microsoft Network versions 1.0, 1.05, 1.2, 1.3, 2.0, 2.5

SUMMARY
Both outbound and inbound e-mail messages have size limits on The Microsoft Network.

MORE INFORMATION
The message size shown in the Inbox, Outbox, or other mail folder is the uncompressed message size. The message size shown in Remote Mail is the compressed message size.

Outbound Messages
Outbound e-mail messages cannot be larger than 2 MB (including header, body, and attachments). If a message is larger, it is sent back to your Inbox with an explanation.

The 2-MB limit is based on the compressed size of the message as it is handled by The Microsoft Network. It is therefore possible to send a message with a large size as reported by Microsoft Exchange's Outbox folder, because the message is not yet compressed. The parts compressed are the files, objects, and messages inserted using the Message command on the Insert menu. The text body is not compressed.

Inbound Messages
Internet messages received by The Microsoft Network are also limited to 2 MB for the entire message and 8K for the message's text body. Internet mail is not compressed because attachments are text encoded using UUENCODE. If a message received from the Internet exceeds 2 MB, The Microsoft Network sends the appropriate error code to the sending service. It is that service's responsibility to inform the sender that the message was not sent.

Note: Outbound and Inbound messages are limited to approximately 1.3 MB with the (POP3) Internet Mail client that is installed with Internet Explorer. MSN 2.5 has an option to use Internet Mail as your email client.