Some of the emails I send are getting sent back to me saying
I have been blocked by spamcop? What is this as I have never had it before.
Thanks

Sounds like it is the recipient that has the blocked list. Are you getting these replies from the same recipients?

Not always the same people.
One person in particular it happens with and then for no reason I will get the mail returned, and yet she replies the next day to me!! Strange

Thanks

It is possible she still gets the message but it is delivered to a Spam folder. Ask her to add your email address to her "approved" list or "White" list