For reporting bugs and making feature requests, you can use the issue tracker. Please search before creating a new ticket and try to have one subject per ticket. Note that you can comment on existing tickets which is always better than creating a duplicate.
Direct feedback can be sent to or you can use the “Help ▸ Send Feedback” menu item in MailMate.
You can also join the mailing list by using the form below. Answers may come quicker on the mailing list since other users might know them.