I am running mac mail with two accounts but it is only sending from one address

Please carefully read Mail Troubleshooting, I'm sure you only need to re-input the settings for the account that is not working.

Your welcome.

I'm having the same issue as the other user, however I am running 4 accounts (earthlink, mobileme, and 2 work ones that are running through network solutions). The only accounts I'm having issues w/ are the ones going through network solutions. That said, the network solutions webmail is working, just not working from my computer and macmail client. I spent an hour on the phone w/ nework solutions, things are working on their end. I've deleted the account and set it up again, to no avail. Also, I ran the diagnostics and everything says it's working, but it's not... Any suggestions?

Then use the same diagnostics! Also please create your own thread, what you are doing is called Threadjacking and considered rude which I am sure is not your intent. Your issue may have similar symptoms but may be totally seperate so by creating your own thread it keeps the issues segrated and not confused.

I did use the same diagnostics, but that didn't work, as it says everything is working, but is NOT. I guess I'm not up to speed on the etiquette for stuff like this, it's my first time...

Then please re-input all email account settings for the offending accounts. One or more may be corrupt and may look OK but isn't.