2-19-16

For the past couple of weeks I've been sending mail to clients whom I've emailed back and forth for years; but recently I discovered that many of my sent emails have not been received; there is no error messages, nothing in the outbox, no sign that there is a problem until I recieved a few calls from clients wondering why I haven't emailed them on schedule; I did they just didn't receive the mailing.  It doesn't seem to happening all the time and like I mentioned without an error message, I don't know where to start looking for the problem.

Has this ever happened to anyone in the community?