I sometimes get bounced by gmail for unknown reasons.
I find that when I send out my blog via gmail twice in one day to my list of 45 recipients, the second one gets bounced.
When that happens and I really want to send out the second blog, I will go to another emailer, in my case Yahoo. That usually works for my 2nd email in the day.
I've also heard that if you put your own email address in the TO line, the BCC's are more likely to get through. I haven't proven that theory, because I still occasionally get bounce backs with my address in the TO line.
Are there any other suggestions on how to assure our 40 to 50 address emailed blogs getting out using gmail or Yahoo without reverting to paid or formal mass email marketing services? My short list of email addresses does not justify that level of service.