my content cannot delete file attachments

Every time I check my emails I have an annoying on My contents page a list of email attachments i try to delete which cannot be done. cannot even hide them as well. These were emails sent to me which i had deleted as being possible virus or phising type programs. It seems to be a challenge to get rid of these on My contents page. Any information would be extremely helpful on this problem i am having.

Thanks,

George