At 11:11 3/10/02 +1200, Simon Lyall wrote:

On Thu, 3 Oct 2002, Simon Byrnand wrote:

...

I have to agree here. By definition email should have a return address if it is "genuine". If the domain name of the "from" address doesn't even exist, then its almost a sure bet that the email is bogus, and I see no reason it should be accepted. Most MTA's seem to default to this action as well.

I guess you don't get email from people who post to newsgroups, most of them use bogus addresses so if they reply via email to a post the address will not be legit ( john(a)notihug.co.nz.nospam sort of thing ).

Most newsreaders I've seen that have email integrated allow you to set a different email address for posting to the news group than for sending email. Even Outlook Express does this. People writing newsreaders know that fake address are almost mandatory to avoid being spammed....Newsreaders that don't have integrated email will be launching the normal email program with normal email address. You definately have a point, but I've honestly never come across this actually happening before.

Checking around I also came across:

From: Promos(a)Glengarry Wines

Which appears to be a legit little mailout sent last week from e-wine(a)Glengarry.co.nz . I didn't see any others in the search.

Are you talking about the envelope-sender address or the "From:" header ? It looks like you're talking about the From: header here. I'm (and presumably Chris was) talking about the envelope from address, as exchanged at the beginning of the SMTP transaction...

Our spam filtering also has a "No MX for From address" rules that helps block those. Still if you feel comfortable blocking customer's email on that basis I guess it's your choice.

It's not part of a spam filter, its just a standard sendmail setting, which defaults to on. (I could turn it off if I wanted to) You made me curious though, so I did a quick survey of the ISP's listed in iMAG to see if they'd accept a message with a bogus domain as an envelope from address: (not a very scientific survey, but..) Actrix: Yes Baycity: No Clear Net: No Ezysurf: No E3: No HyperNet: Yes Iconz: No Igrin: No Ihug: Yes Inspire: No Iprolink: Yes Jafa Net: No Kc Computer: No Maxnet: Yes Net4U: Yes Orcon: Yes paradise.net: No Planet: No Quik: No Quicksilver: No Slingshot: Yes Valuenet: Yes Watchdog: Yes Wave: No Worldnet: Yes Xtra: Yes Zip Internet: Yes Thats 13 Yes's, and 14 No's. A couple of remarks - a few are actually virutal ISP's sharing the same mailserver so that would skew the results a bit, also I only checked the primary MX. I also suspect that it really comes down to the defaults of the mailserver in question rather than a thought-out policy, as most (but not all) the servers that rejected the bogus message were sendmail, or looked like sendmail, and that is the default of sendmail. (As an aside, I noticed more than one who were running ancient versions of sendmail that have, umm, known bugs.... ahem :) Regards, Simon Byrnand iGRIN Internet - To unsubscribe from nznog, send email to majordomo(a)list.waikato.ac.nz where the body of your message reads: unsubscribe nznog