FBLs and ISP Management Techniques Explained
A Feed Back Loop (FBL) is a direct data feed that is sent to an email sender when the recipient presses the "Junk" or "Spam" button. The benefit is that the email sender can clean their subscriber data, allowing them to maintain their reputation with Internet Service Providers.
What triggers (flags) cause ISPs to block your email? Sometimes it's a dirty list containing non-deliverable addresses. Other times it's the ratio of spam complaints from that domain, which can include false positives.
Here are the grades for ISP's where legitimate messages were flagged and determined to be false positives: Yahoo! gets an A, Hotmail B, AOL C, and Gmail scores the lowest with a D.
Some techniques to avoid false positives are:
- Don't use words, terms, or phrases in the subject line or message that trigger spam filters
- Understand domain-specific user interfaces to request address book entry. Here are some examples.
- Manage list hygiene to ensure messages are not sent to unknown domains. (Admail.net's system catches these and purges from your list member file)
As always--be aware of your list.