Afraid you're annoying your donors by emailing them too often?
Are you also afraid that you contact them so infrequently they don't know you exist?
Both are potential problems.
But under-emailing is far more common.
There's a "sweet spot" between the extremes, and you can read about it at How to Avoid Being a “Spammer” or Being Forgotten: How Often Should Your Nonprofit Keep In Touch? on the Bloomerang Blog:
... e-mail marketing statistics tell us that between one and two e-mails a week prove to be the most effective. Additionally, good social media practice says to try to post once a day to stay in your audience’s “feed” and top of mind.
Of course, being relevant, interesting, and welcome are part of the job too!
Jeff Brooks has been serving the nonprofit community for more than 30 years and blogging about it since 2005. He considers fundraising the most noble of pursuits and hopes you'll join him in that opinion. You can reach him at jeff [at] jeff-brooks [dot] com. 
