How to stop receiving emails addressed to my self in the junk mail

For some months now,  I have noticed that I have been receiving emails in my junk box, which show they have been sent by myself,  This not the case. I have not sent them at all.  Is this common? Are others finding the same thing happening to them in their junk mail box?  In response I have just kept deleting them from the junk mail box, whereas other junk emails I have been sweeping them and blocking them.  Can any one let me know why this is happening and what can I do about it.  I sometimes find it necessary to send myself an email, but if I swept all the emails that I have received showing that I am the sender, then I would not receive the genuine email that I need. Thanking you in anticipation ......................Angus