Not receiving email

Actually, I loked back and in January one of them was able to send an email to me without an attachment. I am asking the other to send me a message w/o one. So, I think it may be only when they send an attachment, but I will no more later. Also, I am checking both my outlook and the webmail and these emails are not on either.

 

I have 2 different clients that are both in California, but different parts that can not send me email. They send something, but I never receive it. They both had no problems sending me stuff before the migration.