SMTB-754 — Duplicite CR found in end-of-line sequence
Some SMTP client implementations write double CR in end-of-line sequences. It's probably a misuse of the C-language CR escape sequence on Windows platform.
Proxy handles this violation according to the bad-end-of-line setting in particular MAIL-FILTER section. By default, the error is fixed in non-signed mails/documents and passed in signed ones.