Email Newsletter Blog

I have a ministry and I have approx. 400 people on it. I usually have to send out about 100 at a time each hour. This is bothersome but I can deal with it right now. Here’s my problem. Every few months or so I start getting an error message that I have too many addresses in my address field and it will only
let me send out between 25-50 at a time. This is such a pain and it takes me days to get my email out because I cant sit there for hours on end. I have a ministry and I send out a weekly newsletter and everyone on my list has requested to be on it so I am NOT spamming. I’m so sick of YAHOO and this problem occuring. Can anyone tell me how to avoid this.

Thanks.
Melanie Daigle