Hello. It's about a month at least that Special:EmailUser just does not work properly. Many of sent letters do not arrive. I sent 3 letters to @Matanya, he did not get them. Some user sent me a letter with a copy to herself a week ago. I did not get this letter, she did not get the copy, but I did get echo notification about her mail.
See also:
Uhh... Right, so ignore my previous comment. I've been getting yahoo emails in spam *when they post to a mailing list*. I don't remember what happens with Special:EmailUser though, so try using that to send to me on enwiki
I received emails from you, however your sending domain does not match the one you posted above.
User "ביקורת" (User id: 181590) in hewiki claims he received 2 echo notifications in the last 24 hours on emails but didn't actually get them.
Closing as this issue has gone a long time without report of recurrence. If the problem is still occurring please don't hesitate to re-open.