What is "local ISP SMTP mail server?

Mail server profanity filters

• Question for MS Exchange server administrators, or anyone similarly knowledgeable out there, about e-mail censorship... [more inside] My school's SMTP server only accepts messages sent from within the campus network. When I'm off-campus, I get around this problem by directing Outlook to send the message through my ISP's SMTP server (smtp.east.cox.net). I haven't had any issues with this arrangement, until today when I tried sending a couple friends of mine class notes from Friday. I was in kind of an irreverent mood during class and in my undercaffeinated haze dropped the F-bomb, as in "Landlord says to tenant: Get the fuck out. What's tenant's remedy?" I sent the message out this morning to my classmate whose e-mail addy is on the same law school domain. No bounceback or other kind of error message appears. I figure everything's okay. Then I find out that my friend never got the message. Experimentation ensues. I send the message to myself. It never shows up. I send the message to my Yahoo account and my friend's yahoo account. It appears! Next, I send myself a Word attachment with the notes included inside. It appears. Next, I go in through the school's webmail interface and drop the f-bomb in a message to myself. It appears! Finally, I send a swear-laden message from my Yahoo account to my school account. Doesn't show up. So my hypothesis is that anything sent from a non-school SMTP server to a school mail server with a magic swear word (fuck, shit, and ass have been tested so far) never makes it to the recipient, and no bounceback or error message is ever returned to the sender, while anything sent within the network is not censored. I'm concerned - not necessarily for the censorship, which has its own issues, but for the fact that the sender never knows that his message never got through to the recipient. It's always been my experience that netiquette, if not some regulatory mechanism among e-mail servers, demands that notification be sent when the server can either not find or does not want to forward the message to the recipient. Before I send nasty (but swear-free) letters to my school administration demanding that this practice be stopped, is it possible that there's a default setting in MS-Exchange that has never been turned off? Or is the only answer that this practice - including failing to notify the sender - is deliberate?

• Answer:

  fyi, rfcs 821 and 2821 both use the "must" word about failure messages, afaict - http://rfc.sunsite.dk/rfc/rfc821.html http://ftp.rfc-editor.org/in-notes/rfc2821.txt - but i doubt many people do so for spam blacklists (i don't!), so perhaps the attitude is slipping. also, that's only if the message is accepted. if the filtering is done as the message is received it might mever be accepted (i'm guessing - don't know smtp that well), in which case it's the server before that's failing to generate the error report. (incidentally, are you sure it's ms-exchange?)