[lug] MTA poor reputation issue

Zan Lynx zlynx at acm.org
Fri Jun 20 19:02:47 MDT 2014

On 6/20/2014 4:25 PM, Chip Atkinson wrote:
>> My guess is that the previous owner of that IP was a spammer.  One of
>> the joys of getting a new IP address.
>> Orion
> I don't disagree at all.  Like getting a new mobile number and suddenly
> every collection agency wants you.
> I was thinking something like a Raspberry Pi acting as a mail relay to
> and from the cloud machine.  Does this sound feasible or would it
> horribly over tax the Raspberry Pi?

If you are going to run a mail server at your home IP then why not just 
run it there? Or perhaps I don't understand what you're trying to do.

If you want to run a SMTP relay server that is not very taxing on CPU. 
However, it can be hard on your storage since almost all SMTP servers 
write the message to disk and fsync it there before acknowledging email 

If you receive a LOT of email then a slow storage system will limit your 
rate. If I recall correctly some tests I did in the past, a 5,400 RPM 
hard drive SMTP server can do about 5 messages per second. That number 
depends on the filesystem. We were using ext3.

Storage might also be a problem on a rPi if you're using Flash memory 
because SMTP is about the worst possible use for SSD. Small messages 
with fsyncs cause a lot of write amplification and cell wear. I don't 
think SD cards have the best possible wear leveling algorithms either. 
I'd use an external USB hard drive I think. A 2.5" SATA SSD would work too.

Or if you like to live dangerously and your rPi is quickly relaying 
messages to a cloud server you could explore the server daemon's config 
files to discover how to turn off fsync. It is possible to lose a 
message on a crash or sudden power loss that way.

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