[unisog] When you really need to blast email

Steven VanDevender stevev at uoregon.edu
Tue Mar 11 18:24:40 GMT 2008

Michael Holstein writes:
 > Our safety folks are working a campus-wide "emergency notice" system, 
 > where one option will be email (the logic behind that is outside the 
 > scope of this technical question).
 > Yahoo (and others) like to rate-limit email, and we've tried to no avail 
 > to remedy this .. usually we get a "421 try again later" (Yahoo). For 
 > things like our campus mail digest or notices of a snow day, a 15 minute 
 > delay isn't a problem. For something more serious like "stay inside and 
 > away from the window", it is.
 > My first thought was was to configure a box with multiple virtual IPs 
 > (possibly on different subnets) and blast them out in parallel with 
 > hopes of staying underneath the "radar" .. by doing multipath routing 
 > with Neftilter, for example (since I apparently can't do this with 
 > sendmail directly).
 > Is there a better approach than this brute-force hack?

We've had our administration express a similar desire to use email as an
emergency notification tool.  I have tried to consistently emphasize
that in general there's no way to guarantee that email can be made to
reach all intended recipients within any specified time, let alone that
the recipients will actually _check and read_ their mail within the
intended time window.  Of course, at the same time I've tried to
optimize our own email system to at least minimize total delivery time
for mass mailings like this, within reason and the limits of our
available resources.

Any attempt you make to try to circumvent another provider's mail
policies (such as Yahoo's rate-limiting) may just get you labeled as a
spammer, making it even harder to deliver legitimate mail to them.
Think _very carefully_ about what you're trying to do with Yahoo,
especially how it might look from their point of view.  I have to deal
with enough legitimate outside entities who have antisocial mailing
practices (such as qmail-style massive parallel delivery) that I have
resorted to installing rate limits on some of them to keep our mail
system from being crushed by their overenthusiasm.

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