EMailAddresses is a String property that represents the contents of the collection as a comma-delimited list of email addresses in RFC 2822-compliant form. 

Reading the value in EMailAddresses results in a string that contains a comma-delimited list of values for each TIdEmailAddressItem in collection. 

Writing to EMailAddresses will call Clear to empty the collection, and add each EMail address parsed from the new property value to the collection. Please note that Group EMail addresses, delimited with the ":" (colon) and ";" (semi-colon) characters, are ignored when email addresses are added to the collection.

TIdEMailAddressItem