Subject: Re: designate an email address for testing at any provider

From: Joel Jaeggli <[email-masked]>
Date: Wed, 01 Apr 2009 23:46:36 -0700

Nick Levinson wrote:
> I think you didn't mean domain. In that case, the catchall address
> encourages delivery. I'm looking for a guaranteed bounce, for test
> purposes, at any email service provider.

Well know addresses tend to create opportunities for DOS.

Two other issues, such an approach would make it easier to evaluate what
criterion a system is using to accept mail, which many people obviously
are reluctant to do. Secondly forging to sender produces the opportunity
to DOS a third-party.

> If you did mean domain, domains like example.com would give a
> different result than sending to a real domain.
> 
> The same address at any provider would be better.
>

---

From: "Olivier MJ Crepin-Leblond" <[email-masked]>
Date: Fri, 3 Apr 2009 01:08:56 +0200

> are reluctant to do. Secondly forging to sender produces the 

+1.
Very very very bad idea to have a guaranteed bounce address.
Back in the days, we could send email loops out by relaying via third 
parties. That feature was taken out when spammers started using it. 
There were also bounce servers which you could use to test out your 
email. There are only a handful remaining (several DKIM test, for 
example) , and I believe even these are being abused.

Any properly set-up email system will now outright reject email to an 
unknown recipient. Some don't and are immediately used for 
back-scattering, and soon enough, end up on the anti-spam block lists. 
Many places not break the RFCs and do not bounce email back: incorrect 
recipient goes to a black hole. Last but not least, many bounces now 
also get caught by anti-spam filters which means that even though your 
email has bounced, the bounce gets weeded out by the filters.

Email's already become unreliable enough without opening new doors to 
spammers to make it even worse. If you want to bounce emails back to 
you, send to a random 12 alphanumeric characters to the left of the 
address, so no need to a standard bounce address. This is already used 
by spammers.

Kind regards,

Olivier

-- 
Olivier MJ Crépin-Leblond, PhD
http://www.gih.com/ocl.html