ISPs recognize that some methods of spam-fighting may inadvertently catch legitimate email. To that end, some of the biggest ISPs have developed processes that help marketers stand out from the spam noise and get their messages into the inbox.
Get whitelisted
Most marketers are familiar with blacklists. If your IPs are added to a blacklist, your deliverability will go down the tubes. Not surprisingly, whitelists have the opposite effect. ISP-based whitelists will aid -- but not guarantee -- delivery into the inbox versus the bulk folder. Whitelisting in AOL, for example, relaxes the limits on the allowed bounce rates and sending speeds, giving you greater flexibility to deliver mail.
Typically, you will have to make some assertions about your marketing and permission policies, and you will be required to maintain a certain level of IP reputation to meet whitelisting criteria.
One of the best sender-facing postmaster resources from an ISP is AOL's Postmaster page. It includes resources to set up whitelisting, feedback loops and bounce information.
Use feedback loops
Some of the biggest ISPs are offering email senders the ability to review whether readers are marking email messages as spam. These mechanisms, known as feedback loops, will send you an email message every time an ISP subscriber clicks the "report spam" button on one of your messages. The volume of feedback generated may be anywhere from a few hundred to multiple thousands per day, depending on the volume you send.
Feedback represents a direct glimpse into the ISP reputation system. You can trivially identify how many messages you sent to one ISP and how many of their readers marked your messages as spam. There is no feasible way to dispute erroneous complaints, so try to think of this mechanism as a gauge of reader satisfaction with your messages.
The primary causes of a high spam-complaint ratio are lax permission policies. You can imagine that with a mailing list harvested from websites or registration information, unsolicited mailings will generate huge complaint numbers, which will lead to blocking very quickly.
For legitimate marketers, however, one of the biggest contributors to high spam complaints are ambiguous subject lines and "from" lines. Recipients use these two fields to base their split-second decision to open/delete/report spam, so make sure that your email quickly and effectively stands out in their inbox. Branding the subject line with consistent messaging and brand names seems to be the most effective.
For example, compare the below example subject lines from "Brickhouse," a fictitious clothing retailer:- 50 percent savings on your favorite clothing lines! Deal expires soon! Act fast!
- Exclusive members sales event, priority coupon inside
A subscriber to Brickhouse's lists will immediately key in on the second example due to the branding, especially if it's consistent across all email communications, both transactional (order, shipping confirmations) and promotional.
Some of the ISPs that currently offer feedback loops include AOL, Hotmail, EarthLink, Juno/NetZero and Outblaze.
Yahoo's feedback loop is coming soon. Sign up for all of them and use them not just to unsubscribe complainants, but also to gain meaningful feedback from your recipients.