Every year a church should sent out gift letters (statements of contribution) five times a year. After each quarter AND the first week of December. That letter in early December may be a new thing to some church administrators, so let me explain why you should do it.
December is one of two times a year that people's giving is heightened by society (tax filing season in April is the other time). A professional fundraiser once told me that he needs to work only two times a year, April and December, because those are the times when people are most inclined to give. The rest of the year he cultivates donors, and there are some good lessons in that for church administrators. Since people are already aware of the Christmas season of giving, leverage that awareness for the good of the church by sending out a statement of contribution.
Most people do not record during the year how much they've given to their church. They need reminders and a letter in early December is an easy way to let them know. Most people are not offended by such a letter, and a lot of people actually appreciate the reminder.
A gift letter in December pays for itself several times over. Yes, it costs money to send out the letter, but my experience is that the amount of money received is a lot more than it cost to send out the letter. Sending it out is very cost effective and beneficial to the church (and to the donor for tax purposes).
Send a gift letter out (with a cover letter) in early December and you won't regret it; it will help you get in some year-end gifts that you might otherwise have not received.