When users send an e-mail with 64,000 or more characters and an attachment from GIFTS or E-Mail Plus through an SMTP server, the text of the message is received as an attachment and the recipient cannot open the file that had been intended as the attachment (when the recipient attempts to open the attachment, it is displayed in plain text code instead of its correct file format). 

When sending e-mail messages with attachments, limit the number of characters in your messages to less than 64,000.