Ruby,
Just some thoughts...
Has your company recently started using some "gateway" software, such as a firewall, or proxy service? Has the company started using a new antivirus program maybe? All of the above could be blocking the e-mail from being sent/recived correctly but shouldn't be the cause of disruption on every machine unless the "block" is at a gateway server of some sort..
If none of the above applies, then it sounds like a problem with your Internet Service Provider. The ISP provides all addresses for the company and is responsible for making sure that it works correctly. It should be their tech folks that fix the issue.
Hope this helps.
Grif
We use outlook express as our e-mail handler in our business. This just recently started but all RCN addressed e-mails are returned "user unknown". I am an RCN client and I emailed myself at work, received it just fine, and then when I replied it came back "user unknown". Someone suggested I add a signature to my e-mails and I'm going to try that. My web guy says it's not his mail server. RCN customer service leaves much to be desired, no answers there. Any suggestions? Your help will be greatly appreciated.

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