[Exim] Mail containing single line dot

Hello

I'm new to this list, so please excuse, that I start asking, since I know I
should observe the list at first. And I should also search the archive. But
I have tried the last but according to the special type of question, I
havn't found what I have searched for.

But now to the problem.

I have 9 mails in a maildir created by exim 4.30#1 on debian sarge.
The problem is, that these 9 mails have lines only containing a single dot.

How is this possible. Exim should stop acepting content lines after a line
with a single dot, shouldn't it?

BTW all the mails are from ebay.

For me this problem is somehow urgend, since we need to use some software to
collect mail from these mailboxes and hand them over to another smtp server.
This transmission fails because of the single line containing the dot.

(Yes, it would be easy to remove that, but I want to understand why I can
happen in the first place.)

Thanks,

Steffen