Oh dear. All those "emails". Have I interpreted this correctly? <blockquote> I would like to create an email '''address '''list to which thunderbird should not send email '''messages'''. How do i do this? I send promotional email '''messages '''and sometimes people say ' do not send me email '''messages''''. I would like thunderbird to remember these email '''addresses'''. Please help </blockquote> You probably need some proper CRM software to manage this. You could create separate address books, or mailing lists, for regular and "no contact" customers. The MoreFunctionsForAddressBook add-on allows you to associate specific address books with each account, so you could at least discourage the inclusion of "no contact" addresses, but the success of this somewhat depends on how you create your mailing runs. You could create outgoing filters, based on inclusion in a specific address book, but I can't think how to make it do anything useful. I suspect a mail merge could be used, and be made to employ a conditional test on some entry in the CSV data file that tells it whether or not to include a particular address. In short, I think this is outside the capabilities of a regular email client.