How do I delete mail?

[Lorne]

I have 3 emails in my inbox that will not delete. They just turn grey and stay there. When I open them the message is gone but they remain in the inbox.
Just a little annoyance.
Lorne

[Lorne]

I managed to get rid of those unwanted emails although I'm not sure why it worked. I went into mail preferences and unchecked the "move deleted messages to a separate folder" and was then able to delete those 3 emails.
Lorne