Since a few days, I'm getting a lot of "Messages with no data size" in the Daily Mail Report, and theses mail are not counted in the sent/received emails.

I tried to search, but didn't found anything revelant.

Messages with no size data
 001FD5E3148  ssonnt@domain.com
 0021C5E32E9  adute@domain.com
 006385E3281  kblabod@domain.com
 0081B5E31C2  rlenry@domain.com
 009475D4E07  dbi@domainain.com
 0095A5E33B8  llespier@domain.com
 00A3F5E32D5  phleayer@domain.com
 00A4A5E338E  rlenry@domain.com
 00DB75DB07F  jlmond@domain.com
 00FF85E32FF  jsilva@domain.com
What could I do ??