The third "history" item in T137603 reads: "@Quiddity mentioned this in T134886: Special:EmailUser emails sometimes not delivered due to bounce. Fri, Jun 10, 22:42". However, the history for T134886 only says: "@Quiddity mentioned this in T137603: Block Special:EmailUser for people with a DMARC-problem address. Fri, Jun 10, 22:42".
So it looks as if just logging was treated the same way as a comment/description edit.