I am in the process of setting up mass email service.

My question is: what are the best practices to achieve maximum deliver-ability.

More precisely - what should I do/know to prevent spam filters from blocking the emails (the emails are not spam).

for example- how can I tell if my IP address is blacklisted somewhere and how can I prevent it from becoming blacklisted. Is amazon web services a suitable platform due to dynamic IP addresses, what are the restrictions on the from address, can it be different from the mail server domain.... you get it....

  • From what I've seen, current spam solutions are just failures. None of them work and do more to blacklist legitimate mail than anything. – Chris Marisic Apr 27 '10 at 19:10
  • Depends. Less than 15% of all email connections to the server I watch over are actually legitimate; the remaining 85% are spam. Out of the '85%' spam that contacts the server, my spam filters typically see about a 95% capture rate with no false positives, and that's when I'm not giving it the attention I should. I can tighten it up more and get the number up to 98-99%, but past that point it becomes a diminishing return. – Avery Payne Apr 28 '10 at 1:33
  • @Avery and who determines whether it was a false positive, you or the recipient of the email? Because I'm 100% right 100% of the time if I determine whether I'm right. – Chris Marisic Apr 29 '10 at 19:22
  • That is a question of examination of the contents of the email. If you are promoting samples of Cialis and Viagra, then no, that has nothing to do with the line of work I am in. If a determination cannot be made, then the user is contacted and questions are asked; if there is a really good compelling business reason (i.e. something that profits the company) for receiving Cialis and Viagra samples, then sure, it'll go through just fine. Of course, what Cialis/Viargra has to do with selling fresh vegetables and fruit, well, I don't want to imagine how those go together. – Avery Payne Apr 29 '10 at 19:49
  • @Avery I think we're talking about 2 very different things at this point, I'm talking about solicited bulk mail, not spam. – Chris Marisic Apr 29 '10 at 20:54

Frankly the best way is not to do mass emails from anything remotely related to your domain. By definition anything unsolicited mass emailed is spam. If it's solicited then the recipients will whitelist it.

  • +1 for a view "on the other side of the fence" (as an email admin). It's not a big deal with legit opt-in email, generally that stuff flies through just fine; but if you have enough "spammy" attributes, no amount of whitelisting in the world will save you. – Avery Payne Apr 27 '10 at 17:07

The short of it is: it's up to the recipient's site admin as far as what goes and what doesn't. Trying to make it so that it "100% goes through" is an exercise in futulity, because the admin at each site will have different policies on what is "valid". So if you want this to work, follow these simple rules:

  1. Always sent to opt-in recipients, with an option to opt-out. Unsolicited means just that, and you'll just create animosity by not having recipients that asked for your email in the first place.

  2. Don't get all drunk-happy with bizarre HTML formatting or all-images-mail, you'll just trigger filters. Good formatting is courteous and makes your offers look professional. Bad formatting often triggers a 'spam' tag.

  3. Make sure your server follows SMTP guidelines, or you'll just get rejected (many spammers don't play by the rules and often send "broken" SMTP sequences, etc. in an effort to carpet-bomb as many messages as possible in the least amount of time)

  4. Be reasonable about delivery rates, attempting to machinegun 1,000 mailings though a single connection is a sure-fire way to piss off the site's admin (or at least kick the rate limiter into the ON position), but sending one recipient at a time with 3 parallel deliveries might be acceptable.

  5. Accept the fact that some sites simply don't want to talk to you, no matter how much you want to talk to them. This goes hand-in-hand with the following corollary:

  6. The email server is owned by the site you're sending to, so they have every right to make a decision about how to treat the delivery of your message; this includes putting the message in quarantine, or even piping it to /dev/null

  • I won't DV but I would strongly disagree with 5&6, it is the user of the email system that SHOULD determine what happens to mails, not the admin. – Chris Marisic Apr 27 '10 at 19:08
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    Actually 5&6 are right on the money... It is the admin's responsibility to maintain the integrity of the mail server and if they feel something is unwarranted, unsolicited and/or causing performance issues they have the obligation to take action which is usually to block the offending server. The users can go elsewhere if they want, one mailbox on a shared system can't cause a disruption for many. – Jeremy Bouse Apr 27 '10 at 19:45
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    I agree with Jeremy, the Users are using MY email system. Until my company tells me otherwise I'm responsible for keeping it alive and I'm not about to clog it up with marketing crud just because they signed up for a constant contact email campaign using MY domain. – Jim B Apr 27 '10 at 20:04
  • @Chris Marisic, I can understand your position, but email service policy typically falls under the realm of the email administrator first, and the user second. This seems harsh and draconian, but the goal is for the admin to set 'upper limits' and policy, and let the user decide from there what to do inside of that. Getting your server blacklisted by the actions of a single nefarious user is hardly ideal, and with other accounts on that machine suffering the consequences of that one 'bad' person's action(s), it suddenly doesn't seem so draconian a measure. – Avery Payne Apr 28 '10 at 1:28
  • @Jim B, I seriously hope you don't take that position as an operator of that inside a business, those marketing emails could be nearly integral to a business user. – Chris Marisic Apr 29 '10 at 19:21

I know it's late, but you are probably best off to use a Commercial Service for this type of E-Mail. They have a wealth of experience, and are usually way better in making sure e-mails get delivered than you can ever be.


I can't help you with all your question but this is where I check our IPs to see if they are blacklisted or not; MXToolBox. I try to do this daily but at least twice a week.

We've also setup various Feedback Loops with some emails hosts (RoadRunner, AOL, etc). Check out this whitepaper on it: http://www.datranmedia.com/downloads/whitepaper_feedbackloops.pdf. This makes you more legit and professional.

Hope this helps you!

  1. Use software like PHPList to ensure that you do not send emails to people who do not want it.

  2. Take this Email Server Test and implement its suggestions so that your emails do not appear like SPAM.

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