I just traded email with a friend of mine. My initial response to him included a swear word (I know, I know, apparently I am a little evil - but only prime-time-tv evil). Apparently our spam filter on our gateway rejects incoming mail due to language, but not outgoing email. That must actually cut down on a lot of email that's intended for me. :)
>Wow, chris can curse in his emails, but we can't curse in the emails to HIM.
PERM_FAILURE: SMTP Error (state 12): 550 5.7.1 <Your e-mail was rejected by an anti-spam content filter on gateway (18.104.22.168).Reasons for rejection may be: obscene language, graphics, or spam-like characteristics. Removing these may let the e-mail through the filter.>