Savemail panic

[Bingrui Foo]

I just installed FreeBSD and even reinstalled it, but keep getting this
error message about once a day:

May 22 03:01:03 sendmail[1813]: h4M8133q001813: Losing ./qfh3M8133q001813:
savemail panic
May 22 03:01:03 sendmail[1813]: h4M8133q001813: SYSERR(root): savemail:
cannot save rejected email anywhere
.... (message x 2)

Wonder what is the problem. I have tried to disable sendmail using rc.conf
but it doesn't do anything.

Foo