Auctions can be automatically relisted if you do not receive any bids and this setting is checked when you list your auction. In order to keep the auctions on the site fresh and up-to-date there is a relist limit of 10 times. If you enabled email notifications for relisted auctions ("Send me email when my auctions are auto relisted") you will get an email both when your auction will be relisted for the last time and when it has been removed. If you do not have this notification setting enabled you will not receive any email messages related to your auctions being relisted or removed due to hitting the limit.