1) Make sure your e-mail server—or your ESP’s—is configured correctly. If you maintain your own e-mail server, it’s crucial that it’s set up correctly. If not, Bilbrey said, you run the risk of being classified as an illegitimate server. This means making sure your reverse DNS settings—which map an IP address to a host name—are correct and use your domain name. “You don’t want to have a big string of numbers. You want it to say, ‘mail.domainname.com,’ ” he added.
2) Keep your unknown user rate down. When you send out an e-mail to someone who doesn’t exist, the ISP or server that’s handling that e-mail keeps track of that delivery attempt. Log too many of those attempts and you risk being placed on a black list or blocked at the server level. If that happens, none of your e-mails to that domain or ISP will get through. This can happen when e-mail recipients change jobs or don’t log in to their e-mail address frequently. Your best bet, Bilbrey said, is to check for unknown users after every mailing and remove them immediately. Your IT person or ESP should be able to provide you with a list of bounced e-mail addresses and help you remove them.
3) Track your reputation. Companies such as Return Path track e-mail senders’ reputations based it on a variety of information such as inclusion on black lists, complaint rates and e-mail volume. Keeping track of your score will give you an idea of your deliverability rates because reputation scores tend to correlate with deliverability, Bilbrey said. “It’s definitely a case of the higher the score, the higher the deliverability,” he said. You don’t need to subscribe to a service to check on your reputation. Return Path provides a free service at senderscore.org, for example.
4) E-mail often. If you don’t e-mail your list often enough, e-mail addresses can become stale. This means you may end up with more undeliverable messages than you would like. In addition, even if your messages do get through, recipients may forget that they signed up for your messages and report you as a spammer. The fix, Bilbrey said, is to make sure you reach out to your list at least quarterly, although monthly is even better. “With triggered events, the condition that triggers an e-mail may never occur,” he said. “It’s good to send out quarterly messages to weed out bad addresses right away.”
5) Don’t get caught in a spam trap. ISPs and large domain holders may set up spam traps, placing e-mail addresses that don’t belong to anyone on their home page or around the Web to thwart those spammers engaged in e-mail harvesting. You can end up sending to one of these addresses if someone maliciously signs one of these addresses up for your list or if a legitimate e-mail address is entered incorrectly. You have two ways of preventing this problem, Bilbrey said. The first is to implement a double opt-in so you can verify every address before it goes on your list. The second is to e-mail double opt-in e-mail messages from a separate domain as well as a separate IP address. “If you do hit a spam trap and get on a black list, you can go to the ISP or the domain owner and say, ‘This is my confirmed opt-in welcome stream. I can’t control what people input. That’s why I have a double opt-in in place,’ ” he said. “The ISP sees you’re trying to do the right thing and, as long as you provide some evidence that that’s what you’re doing, you won’t have a problem getting off the black list and at the same time, the rest of your e-mail list is safe.”