attachment can only be read the third time

[lunar_316]

this is the strangest phenomenon. We are unable to open any type of attachment from this one firm. But when they send the same attachment the third try, we are able to open the attachment! these are simple ms office files (excel, word, ppt, etc...)

We've set up a internet mail account to receive these emails and we're opening these
attachments fine.

I'm stumped as to why. Why only after the third try? And it happens every time! Any ideas?

We're running Exchange 5.5 sp4 for exchange, NT 4.0 sp4 w/ Trend Scanmail.