Asset share link mail issue on aem 6.5.4

I found the email sent by asset share link function has no content(I have inputted the message), the email only has a subject.

(There are none exceptions in error.log)

In Day CQ Mail Service Configuration, I set Debug.email=true, below is part of mail, mail content hasn't been printed out.

---------------------------------------------------------------------------

Log ： 

Subject: share link
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="----=_Part_140_996355459.1589520583239"

.
250 2.0.0 Ok: queued as 4BA74BE094A
QUIT

--------------------------------------------------------------------------

I compared bundles, dependencies versions related to mail function between 6.5.0 and 6.5.4, I found JavaMail API 1.6.2 has been included in sp 6.5.4, when I stopped the JavaMail API 1.6.2 bundle (turn to a Resolved status), it works, I can see the whole email now.

Anyone encountered this problem??? any other way to solve this???