lmtpd: Trying to unput wrong character

[Mark]

Good day,

I've recently received some emails (from Nokia's mailing list) that give
me the following error when handed over to cyrus lmtpd for delivery:

4.3.0 lmtpd: Trying to unput wrong character (in reply to end of DATA
command)

The emails are then stuck in the queue until manually deleted.

I haven't debugged it in detail, but it looks like it's probably
triggered by innovative end-of-lines characters in the incoming email.
The end-of-line character sequence is  0d 00 0a (looking at the Postfix
queue).

Presumably this is non-standard. Should it be something that Cyrus
handles better, or should be something that Postfix repairs or rejects?

Thanks
Mark