Edit your incoming SMTP policy. Go to the Properties tab, click the View/Edit Proxy button next to the Proxy Action drop-down. Under General -> Greeting Rules. Make sure that you are in Advanced View. Find the entry labeled Non-Allowed characters, click the Edit... button. In the Rule Settings area, find the Regular Expression that is listed, it should look something like this [^-.0-9a-zA-Z_[red]\[/red][\]]. Before the \ marked in red, add the apostrophe. The expression should now look like this [^-.0-9a-zA-Z_[green]'[/green]\[\]]. Click OK three times to get back to the Policy Manager and save the config to the Firebox.
I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)