Chris-Linfoot.net

... a broken POP3 fetch.

Picture this. Some time late last night, Johnny Salesman (not his real name) decides, having neglected to get around to sending any Christmas cards (that is the women's job, right?), to rectify his oversight by sending an email to his entire contact list (some 302 people/companies). He does this using the To: field and now feels so much better.

* One (yes, fortunately only one) of the recipients is using a POP mailbox and a POP3 fetch to retrieve Internet email for re-insertion into a local SMTP based delivery system (yes, we've been here before - more than once too - sue me).

That POP3 fetch is badly broken.

While some attempt has indeed been made to preserve the SMTP envelope data during the POP phase (using an additional X- header to record envelope recipient), the POP connector at the other end has simply ignored this piece of data. Instead it has reassembled sender envelope or SMTP MAIL FROM using the RFC2822 From: field of the message (correct as luck would have it) and recipient envelopes or SMTP RCPT TO from the RFC2822 To: field (incorrect, outnumbering as they do the correct envelope recipient by a factor of 302). Oops.

Remember, this is one of the recipients of the original piece of seasonal goodwill, and he now sends out 302 fresh copies of the message to his own service provider for onward delivery. Including one addressed to himself.

Provider duly obliges and before long that fresh copy hits that same POP user's own POP mailbox. The POP fetch kicks in again and...

Oh I can't be bothered. Just go back to * now and keep reading.

As of right now, each and every one of those 302 recipients of a little Christmas cheer has 132 copies of it in their in-box. Plus so far 9 copies of a complaint from one of the other victims who hit "reply to all".

Category: Dumb and Dumber
Technorati: Dumb and Dumber

1. Eric Parsons16/12/2004 19:16:06
Homepage: http://www.startingblockcomputing.com

We shut down Mail forwarding agents after, not one, but about three times we had someone sending all their business mail to their home account. The home account system rejects the message with a DSN (because they are over quota, go figure). DSN (NDR for those M$ who cannot read RFC's) is a new message that is in-turn forwarded, only to be rejected. (goto top and reread until you get the picture).

One such case, our client went from several MB to over 13 Gb before we discovered the issue. A 2mb limit on messages, saved our bacon that day. Thank IBM for putting the User rules mail forwarding: setting on the Configuration Document. That's disabled, and will stay that way as long as I have a say.

Personally, I think the "reply to all" should have a "Are you really sure these three thousand people who really didn't want the message in the first place need to have your two cents also?" dialog.

And Happy Holidays to you Mr. Linfoot. I will forgo an email card this year.

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2. Chris Linfoot16/12/2004 19:54:13

Bother - just sent one - check your spam folder

BTW I should stress that Johnny Salesman is not one of my users. But 3 of the lucky recipients of his goodwill are...

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