On Fri, 2010-03-05 at 09:08 -0600, David E. Smith wrote:
As long as we're going off-topic, might as well go all the way :V
Well, the conversation has continued here despite repeated mentions of mailop@mailop.org so unless the MLC deem it off-topic and squash the thread I guess it'll rumble on. My reply below, although based on email, is most definitely on-topic as it covers "good neighbo(u)r" behaviour and could just as easily apply to all manner of bits and protocols which members of this list shovel around daily. Anyway:
How long should a sender (say, Facebook) retain a database of 5xx SMTP responses? Just because jimbob@school.edu doesn't exist today, doesn't mean that James Robert Jones won't enroll in the fall and get jimbob@ as his school-provided email address.
Then that would be spam, would it not? The incoming jimbob isn't the one who left. The incoming jimbob doesn't want to hear about the old jimbob's friends "fun night out", or be invited to their stag parties, or receive discriminatory, lewd or offensive material. Context: in $dayjob we have a delay before re-using usernames. Student email addresses are never re-used, but many students use the "short" form - user@domain - of their email address to register with Facebook. [As a consequence of this problem alone, their ability to do so is being phased out] This academic year alone I have had to request Facebook strip an address from an account several times, 2 of which were for accounts which expired here over 12 months previously. In each of those cases, Facebook had been repeatedly attempting delivery of notifications/invitations and so on since the account had expired. *That's* why I mentioned it. If they had any decency they would trap those 5xx errors and do something to the account with the failing address after some period/number of failures. You know, a bit like Mailman, Sympa and other decent mailing list applications do. And yes, in at least one of the aforementioned cases the incoming recipient was clearly very upset at the emails they were receiving. So it isn't that surprising that they occasionally hit spamtraps or have complaints made against them which result in DNSBL entries. If they played nicely and observed the responses to their outgoing email stream, then it would be far less likely to happen. I guess the return question is: how long should a given operator return 5xx responses to increasing numbers of Facebook emails before trying to do something about it? Graeme