Number one of seven in our occasional series on why ESPs need, or don’t need, lots of IP addresses to send mail properly. I need at least one IP address per customer, to handle IP based reputation Why this is right While DKIM is gradually moving the main key for reputation tracking to a domain based token, right now the main key that is used to track reputation is the sending IP address. If...
In my last post I discussed the background as to why an ISP will require their users to use their IP address allocation efficiently. I also mentioned in passing that I’d discussed ESP address allocation with both ESPs and ISPs recently. The ESP was talking about assigning a couple of dozen IP addresses to each customer, because they might be useful for spreading load and it would provide...
IP addresses aren’t an unlimited resource, not on the current version of the Internet anyway. There are only a limited number of them and, while some of the doom and gloom proclamations about us running out in the next year or two may be exaggerated, we are running low on them and should be conserving them where we can. An ISP can’t create new IP addresses from whole cloth. Instead...
What do you do when you have a potential customers name and address, but know nothing else about them? You’d really like to be able to send them some targeted marketing, ideally via email. You send them a good old-fashioned letter asking them to volunteer more contact information and answers to a bunch of business classification questions – “What industry are you in?”...
Spamhaus announced today that they are rolling out a new system to detect snowshoe spammers. What is a snowshoe spammer? Snowshoe spammers send spam not from compromised servers or botnets, but from large numbers of IP addresses that they are using legitimately. They try to stay below the radar of spam filters, and so get their unwanted email through to the inbox, by looking like a lot of little...
I see a lot of requests for help with some sort of delivery problem, sent to me as an individual, sent to Laura as part of a consulting relationship, sent to ISPs, sent to organizations running blacklists or sent to industry mailing lists, both public and private. Some of them could be done better. OK, most of them could be done better, some of them could be done a lot better. Here’s some...
As promised last week, here are some actual recommendations for handling email addresses. First some things to check when capturing an email address from a user, or when importing a list. These will exclude some legitimate email addresses, but not any that anyone is likely to actually be using. And they’ll allow in some email addresses that are technically not legal, by erring on the side...
Yesterday I talked about the technical definitions of an email address. Eventually on Monday I’m going to talk about some useful day-to-day rules about email address acquisition and analysis, but first I’m going to take a detour into tagging or mailboxing email addresses. Tagging an email address is something the owner of an email address can do to make it easier to handle incoming...
Given we deal with email addresses every day, dozens or thousands or millions of them, it seems a bit strange to ask what an email address is – but given some of the problems people have with the grubbier corners of address syntax it’s actually an interesting question. There are two real standards that define what is a valid email address and what isn’t. The most complex is RFC...
This morning I got spam about college basketball – Subject: Inside: your ESPN Tourney Guide. That’s anything but unusual, but this spam got through my spam filters and into my inbox. That’s a rare enough event that I’m already annoyed before I click on the mail in order to mark it as spam. Wait a second, the spam claims to be from Adobe. And it’s sent to a tagged...
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