exception in XI sender mail adapter

Hi,

XI sender mail adapter raised the following exception when it was fetching emails from a mailbox on a MS mail server while these mails were sent from a unix system.

Adapter-Error: exception caught during processing mail message [1]com.sap.aii.messaging.lang.com.sap.aii.messaging.lang.BinaryIndexOutOfBoundsException: Binary index out of range: -3

However if I sent the same attachment to the same mailbox from yahoo the XI sender mail adapter can process it correctly.

I would appreciate if somebody could share his/her expertise or experience regarding this issue.

Many thanks.

Zhongliang