Why is group email not sending?

What if any message appears when sending fails? The number, itself, is not a problem unless your provider has a limit.

Is there an address in the To header? Is the Group name in the header, but individual addresses hidden?

Ernie

Does this happen quickly, or does it spend some time trying to send, and then present this message?

Ernie

When sending, if you open the Activity monitor in Mail, which apparently you have, you will a period in which it is in the process of connecting to the SMTP, followed by a period of Sending Data with % completed. Is the period of connecting quick and moves on to Sending data where it fails? If this is the scenario, then you may have an issue with MTU (maximum transmission unit) and packet size brought on either by something your ISP has changed, or by your Mac now sending bigger packets faster, until the connection times out trying to manage the transmission. See the following article about how to test if this is the problem -- also are you connected to a modem or router via ethernet, or to a wireless router via Airport?

http://docs.info.apple.com/article.html?artnum=303192

Let us know the result, and also how connected.

Ernie

I am having the same problem. Under activity, smtp quickly connects then sending goes on for a while followed by the error box. This seemed to happen gradually over several weeks. Occasionally the request for an alternate server popped up and if I selected one, the message sent. Then, in the last few days nothing. I tried decreasing the group size, and that did not work either. I am connected to a cable modum and my ISP (earthlink) says my speed is good.

I've encountered the same issue. I also use earthlink as my isp but use Mac Mail for my app. I've found that if I put the group in the bcc window and address the email to myself, the messages go everytime. I actually am good with this because I don't want everyone in this group to be able to see everyone else's email address. However when ever I put the group in the To or cc address window I get the same error message you report. Hope this works for you if the bcc option isn't a killer.
jf

Interestingly enough, I set up a yahoo account and did just that. Don't know why it did not occur to me to try it with my regular earthlink account. I suppose because it had always worked fine previously. I used preferences to hide the group's individual names. Maybe that presents some problem on the 'to' line.
Anyway, thanks bunches for responding!