Email newsletter

Lately whenever I try to compose an email to more than 1 contact from my address book, whenever I click ‘compose,’ instead of taking me to the page where I type in my message, it re-routes me back to my mail home page. I used to be able to send emails to 100 people at a time. Now I keep getting this error. I have also tried lowering the # of contacts selected - it doesn’t work? Anyone know the solution? I experienced this once before but it seemed to go away after several weeks. Please help, as I need to be sending my weekly newsletter!

Thanks

I have to send one newsletter to many individuals on my mailing list and I need to be able to use one word such as entire list or one word to send it out.