Missing email

I have Windows Live mail & just recently a particular email sender (My employer) when they send me an email it just disappears? I managed to quickly read one today it once I closed the pdf file attached the entire message disappeared? No other sender has this happened with just my work email. I checked the blocked sender area & they are not on the list for blocking.I have done a quick repair of windows live but still catch find the missing email. I have also marked the "show all messages" box.Please any help would be fantastic

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