bouncy bouncy
Sep. 15th, 2008 03:02 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
firstfrost(I seem to have shifted from not-posting-at-all to posting-multiple-things.)
So, people get lots of spam. Much of this spam is forged to make it look like it's coming from themselves, or someone else at their domain.
Thus, many IT departments seem to come up with the clever idea: "We shall reject mail that appears to be from foo@ourdomain.com, which is being delivered to foo (or bar) @ourdomain.com, but which is coming from some external mail server." I mean, this looks like a no-brainer, right? Why would internal mail ever be trying to come from an outside source, unless it's Evil?
What this screws over is outside mailing lists. If foo@ourdomain.com sends mail to big-working-group@mit.edu, which has people from ourdomain.com on it, then you get a mail path of ourdomain.com -> mit.edu -> ourdomain.com. So mit.edu tries to hand the mail back to ourdomain.com, and ourdomain.com shrieks in horror, decides that MIT is an evil spammer, and bounces the mail back. Ironically[*], the bounce message has much less trouble getting back to the sender.
*: Is this ironic? All the sarcasm about Alanis Morissette has managed to convince me that things I think are ironic aren't necessarily at all.
So, people get lots of spam. Much of this spam is forged to make it look like it's coming from themselves, or someone else at their domain.
Thus, many IT departments seem to come up with the clever idea: "We shall reject mail that appears to be from foo@ourdomain.com, which is being delivered to foo (or bar) @ourdomain.com, but which is coming from some external mail server." I mean, this looks like a no-brainer, right? Why would internal mail ever be trying to come from an outside source, unless it's Evil?
What this screws over is outside mailing lists. If foo@ourdomain.com sends mail to big-working-group@mit.edu, which has people from ourdomain.com on it, then you get a mail path of ourdomain.com -> mit.edu -> ourdomain.com. So mit.edu tries to hand the mail back to ourdomain.com, and ourdomain.com shrieks in horror, decides that MIT is an evil spammer, and bounces the mail back. Ironically[*], the bounce message has much less trouble getting back to the sender.
*: Is this ironic? All the sarcasm about Alanis Morissette has managed to convince me that things I think are ironic aren't necessarily at all.
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no subject
Date: 2008-09-16 06:19 pm (UTC)no subject
Date: 2008-09-16 09:06 pm (UTC)