sending massive demanding contact

Hello
Since last week, I realize that a large number of members receives requests of contact between buddypress members (bursts of 30 to 40 simultaneously for 1 contact)
Cf image
And of course the members start complaining and unsubscribe.
I looked at the programs level using a script to see the file updates but I do not see anything abnormal.
I have all plugins updated
I found this shortly after updating the plugin to version v: 1.3.13
Can your mail be linked to this problem?
Regards