delivterms
Sender Policy Framework (SPF) is one of two primary types of email authentication mechanisms used by email senders today (the other being DKIM). SPF is a “simpler” protocol than DKIM, in that SPF is based around a text record for your domain name that contains the IP addresses of the mail servers that are allowed to send mail on your behalf.You can lookup the SPF record for Spam Resource here, using my XNND DNS Tools website. As of this writing, that SPF record looks like this:ip4:213.138.100.131 ip6:2607:f2f8:a760::2 ip4:206.125.175.2 include:_spf.google.com -allIt contains two regular IPv4 IP addresses, one IPv6 IP address, and an “include” mechanism that references Google’s SPF record. Decoding this tells us that I want those three servers (with those three IP addresses) to be able to send mail using my domain name spamresource.com, and the “include” for Google is because I am a user of GSuite/Google for Business
DELIVTERMS: The (almost) weekly series here on Spam Resource that defines deliverability terminology. Today, I’m going to talk about Internet Service Providers (ISPs) and Mailbox Providers (MBPs).ISPs and MBPs: Talk to any deliverability consultant and you’ve likely heard the two terms thrown around. What do these acronyms actually mean?ISP means Internet Service Provider, and you’ll find me guilty of using this as a catch all term for any place that a big email sender would be sending email messages to. Even though I include Gmail and Yahoo, on this list, for example, that’s a bit inexact in that true ISPs are companies that provide internet access to their subscribers. Think Comcast and Spectrum.MBP means Mailbox Provider, and that is perhaps a bit more accurately used as a catchall term for any service that provides email addresses for users to receive mail at. How you measure who the largest provider is
DELIVTERMS: The (almost) weekly series here on Spam Resource that defines deliverability terminology. Today, I’m going to talk about DomainKeys Identified Mail (DKIM).What is DKIM? DomainKeys Identified Mail (DKIM) is an email authentication protocol. It is one of two different types of email authentication, the other being known as Sender Policy Framework (SPF). It uses a public/private key pair to generate a cryptographic signature for an email message, and the signature information is stored in a hidden “DKIM Signature” email header. The signature allows a receiving mail server to confirm that the message body (and various email headers) were not modified (that is to say, this is truly what was sent by the sender), and they also effectively identify the sender, when the domain name of the sender is the domain name used in the signature.A public/private key pair involves both a private key, which is a bit of information
DELIVTERMS: The (almost) weekly series here on Spam Resource that defines deliverability terminology. Today, the term and topic is CAN-SPAM.CAN-SPAM, aka “Controlling the Assault of Non-Solicited Pornography And Marketing (CAN-SPAM) Act of 2003” is the US federal anti-spam law. It doesn’t explicitly prohibit spam, but it applies various requirements to commercial email messages sent in the US, and it includes provisions that do help (in my opinion) to push email senders toward opt-in as a best practice.Here on Spam Resource you’ll find a whole section of articles relating to CAN-SPAM, including why you should adhere to the prior affirmative consent standard (because then you don’t have to label your email as an advertisement), what constitutes a transactional message under CAN-SPAM, and I’ll also help you break down four common CAN-SPAM myths. Here I’ll also include links to the full text of the law and the US Federal Trade Commission’s CAN-SPAM
DELIVTERMS: The (almost) weekly series here on Spam Resource that defines deliverability terminology. Today, I’m going to talk about the term Postmaster Site.What is a Postmaster Site? A Postmaster Site (or Page) is a help page or helpful website published by an internet service provider (ISP) or mailbox provider (MBP) that is meant to assist people sending mail to subscribers of that ISP/MBP. If you’re sending mail to Yahoo and that mail gets blocked, the bounce message likely contains a link to specific bounce information that is hosted on Yahoo’s Postmaster Site (or as they like to call it, the Y! Senders Hub).These kind of things are/were called Postmaster Pages (or Sites). Why? Because, “in computers and technology, a postmaster is the administrator of a mail server,” and thus, in many cases, a person dealing with email deliverability issues (especially before the term deliverability was coined) would often be considered an
An email feedback loop (aka ISP feedback loop or complaint feedback loop) is a spam reporting mechanism implement by an internet service provider (ISP) or mailbox provider (MBP) that allows spam complaints to flow back to the sender or sender’s email platform. Those forwarded “report spam” notifications allow the sender or sending platform to unsubscribe those who complain and also to provide sender feedback to understand which clients, lists or campaigns are causing the highest number or percentage of spam complaints.ISPs and MBPs already collect and correlate spam complaint data for their own uses. When you click the “report spam” button in Gmail, or Outlook.com, Yahoo, or elsewhere, those services capture and log your complaint, to feed into their internal spam filtering systems, to generate reputation-related metrics about the sender. Senders who generate more spam complaints are more likely to find themselves blocked, or to find their mail relegated to the spam…
DELIVTERMS: The (almost) weekly series here on Spam Resource that defines deliverability terminology. Today, I’m going to talk about Spamhaus.Spamhaus, in the context of my day-to-day role as a deliverability consultant, is perhaps best described as a publisher of anti-spam blocklists.They publish a multitude of blocklists:SBL: Their primary IP address-based blocking list. Spamming companies and ISPs are listed here both manually, based upon review and investigation by somebody at Spamhaus, and also in an automated fashion using logic that results in “CSS” listings on the SBL. Entities listed on the SBL (for reasons other than CSS) typically have to contact Spamhaus to discuss potential resolution to an issue before Spamhaus will remove (“delist”) an IP address. Spamhaus generally (but perhaps not always) wants to talk to the service provider or sending platform more-so than the end client.DBL: Their primary domain-based blocking list. This is run in a fashion more automated…
DELIVTERMS: The weekly series here on Spam Resource that defines deliverability terminology. Today, I’m going to talk about blocklists.What are blocklists? Also called blocking lists, they are lists of IP addresses and/or domain names that are used as spam filters to plug into various email servers and spam filters. The implication is typically that by inclusion of a particular IP address or domain name on that blocklist, that the publisher of that blocklist perceived or believed that the user or owner of that IP address or domain name was engaged in sending spam, or some other unsavory practice.It was common for some folks to call them “blacklists,” though most operators of blocklists avoided that term. Today, most folks refer to them as “blocklists.”Technical terms that typically refer to a blocklist include:RBL (Realtime Blockhole List): Technically refers (only) to the MAPS RBL, one of the first blocklists, but some folks use…
DELIVTERMS: The weekly series here on Spam Resource that defines deliverability terminology. Today, I’m going to talk about Greylisting.What is it? Greylisting is where an ISP or mailbox provider configures their mail server to temporarily delay incoming email. Usually not long — perhaps for only 60 seconds to a few minutes.How? Mail servers that support this have a setting where they track server connections. If it’s the first time a certain server or domain connects to them, they defer (temporarily reject) that connection or address with a 4xx temporary failure. This invites the sending server to try again later. Most sending mail servers have a “retry interval” setting that governs how long until they retry. In some cases, it’s 15 minutes, in other cases, a few hours. This can usually be configured by the administrator of the sending MTA.Why? It’s a form of spam filtering. It is done to stop…
DELIVTERMS: The weekly series here on Spam Resource that defines deliverability terminology. Today, I’m going to talk about the Friendly From.What is the friendly from? It’s not quite its own separate header, but it is a field in your from header. It is the text that goes next to your email address in the from header.If the from address header in my email looks like this:From: Al Iverson That means that the from address is aiversontestmail@wombatmail.com and the “friendly from” is “Al Iverson.”Some systems enclose the friendly from in quotes, like this:From: “Al Iverson, not a lawyer” This helps prevent formatting glitches in some cases, like if you include a comma in your friendly from. In that case, if you don’t put the whole thing in quotes, there’s a good chance recipients could end up with a very funky looking from address, depending on how their mail application or webmail…