; (semi colon) instead of email address

[Peter Lawton]

When creating a new email and I double click a name in the To / Select Names
dialogue a semi colon appears in message recipents instead of certain
person's contact name or email address. No problem when I add address in a
different way e.g. by dragging contact to the inbox icon.

Only happens with a few contacts - not all

Any ideas please?

Thank you

Peter Lawton