Логи Amavisd

# grep --color -hirC5 all-whitespace $(rpm -ql amavisd-new)
...
- new configuration variable $allow_fixing_improper_header_folding (also
  a member of policy banks) controls fixing improperly folded header fields
  made up entirely of whitespace (prohibited by RFC 2822) by removing
  all-whitespace continuation lines;  defaults to true for backward
  compatibility; fixing such header fields is desirable and can protect
  poorly written mail readers, but may break DomainKeys/DKIM validation of
  messages with illegal header, so if this is of concern, one has a choice
  of turning it off (if local MUAs can't be fixed);
...

/etc/amavisd/amavisd.conf:$final_bad_header_destiny = D_PASS;