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Comment by chrissnell | Hacker News Reader

Be aware: Rackspace (and surely many other cloud server providers) intentionally submit their IP blocks to DNS blacklists to dissuade spammers from using their hosts to send/relay mail. I'm not sure if the other big players do this but it wouldn't surprise me. Same goes for most consumer-class cable modem ISPs.

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I wouldn't say that Rackspace intentionally submits their IP blocks for DNS blacklisting. Consider that on Rackspace's cloud you can build a cloud server and you will get a 'recycled' IP from their block. This IP could had been used by other people for other purposes. You never know who could've used your IP for what purposes. Having those blocks blacklisted makes sense when you think of that.

Do you have any evidence for this? It seems unlikely to me...

He's talking about something called the PBL (policy blocklist). The idea is it contains IP ranges that aren't "supposed" to send mail, like consumer ADSL ranges. People who want to send mail from home directly are supposed to do so via their ISPs SMTP servers, which may be configured to relay but only from IPs the ISP controls.

There is no reason you can't set up your SMTP server to use your ISP, or other SMTP service like gmail, as a smart relay.

Personally I have a VPS that I relay mail through.

One downside with ISP outbound relaying is SPF; if you want to use it you need to figure out how mail exits the ISP and keep the SPF records up to date; and even if you do, suddenly all the other customers of that ISP can fake mail from you while passing SPF.

Another downside is you lose logs of and insight in the mailq and the recipient smtp server responses.

I am familiar with the SpamHaus PBL. It was my understanding that anyone could easily remove their own IP address from the list if required? Presumably that is what happens when Rackspace customers want to send legitimate mail. So why would it cause any problems for spammers?

One of my companies sends hundreds of thousands of emails a month from Rackspace servers. What can you tell me about this ? What blacklists, where ? We don't show up on any of the easily checkable ones.

We are of course CANSPAM compliant, use good email headers, unsub etc. etc.

I setup one a couple days ago on a Rackspace cloud server and anything I've sent from there reaches my Gmail inbox.

By the way, I've used Postfix and it took me like 10 minutes to get it running. I wouldn't call it user friendly, but far from being complex.

I don't know about Rackspace, but if your mailhost is on Amazon EC2, you can use something like authsmtp.com or dyn.com who will sell you smtp relay service for cheap. Easy to setup and use.

Most of Digital Ocean droplets have their IP blocked. I spent several hours last week configuring a mail server only to find out my email were being rejected from hotmail and godaddy.

what was your solution? Others in this thread have mentioned the ability to remove IPs from the ban lists, did you pursue that?

I have an email server with Rackspace and haven't had any issues with delivery.

Really?

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