Friendly From

“Friendly From” addresses

When we’re looking at the technical details of email addresses there are two quite different contexts we talk about.

Most of the time when we’re talking about email addresses, we’re talking about the actual user@domain format that’s used to send mail over the wire, but that’s not how we most often see them. When they’re used in a To: or From: header they’re usually associated with a display name – the “real name” of the user with the associated email address. In the From: field that’s often called the “friendly from”, but the syntax used in the To:, Cc: and Bcc: fields is identical.
The display name is important, as it’s shown more in mail clients than the actual email address is. Some mobile clients don’t display the email address at all, just the display name.
There are three ways you can put an email address in a header field.
The best way is to wrap the email address itself in angle brackets, and put the display name in front of it.

The anatomy of From:

Compared with some of the more complex pieces of the email protocol the From: header seems deceptively simple. But I’ve heard several people be confused about what it’s made up of over the past couple of months, so I thought I’d dig a bit deeper into how it’s defined and how it’s used in practice.
Here’s a simple example:

There are two interesting parts.
The first is what’s technically called the display-name, but more commonly known as the “friendly from” in the bulk email industry. It has no meaning within the email protocol, it’s just text that’s displayed to the recipient to describe who an email was sent by. Because it’s just text, you can put anything you like in there, but it’s usually either the name of the person who wrote the mail or the name of the company or brand that sent it.
The second is the actual email address, the thing with an at-sign in it. Surprisingly, this isn’t used at all during the actual delivery of the email; there’s a hidden field (called the return path or the 5321.MailFrom or the envelope sender or the bounce address) that’s used instead. For person-to-person email it’s usually the same address, but for bulk mail it’s often different.
So what does the actual email address, the 5322.From, mean? For that we go to the document that specifies what email headers mean – RFC 5322, “Internet Message Format”. (RFC 5322 is the updated replacement of the older RFC 822 – and that’s why the actual email address is often called the 822.From or 5322.From when people are being precise about exactly which email address they’re talking about).
RFC 5322 says “The From: field specifies the author of the message, that is, the mailbox of the person or system responsible for the writing of the message.” and “In all cases, the From: field SHOULD NOT contain any mailbox that does not belong to the author of the message”. It’s the email address of the author of the message.
(In some cases the email may have been written by the author, but then sent on their behalf by someone else. RFC 5322 says that in that situation the email address in the From field is still the author of the message. The person who sent the message gets their own field, “Sender:”).
What is the 5322.From used for? During the delivery process it’s used for some sorts of filtering and authentication. In particular, if you’re reading about DMARC you’ll see “identifier alignment” mentioned a lot – which basically means “the only domain we care about authenticating is the one in the 5322.From”. It’s also the usual field that’s used in user-visible mail filtering such as whitelisting email addresses that are in the users address book.
In the mail client itself the most obvious use of the 5322.From is that when you hit reply, that’s the email address your reply will go to by default. The author of the mail can override that by adding a Reply-To field, containing one or more email addresses if they want different behaviour. It’s also commonly used to filter email and to group mails by author.
What’s displayed to the end user? Originally the entire content of the From: header was shown in the recipients mailbox but it’s now fairly common to display just the friendly from, with no mention of the email address at all. That started in mobile clients, where space is at a premium and the friendly from is just, well, friendlier – but it’s spread to desktop and webmail clients too. In Yahoo webmail the 5322.From isn’t displayed anywhere at all unless you find the View Full Header menu option and dig through the raw headers, and my phone doesn’t display it anywhere obvious and only recently made it possible to see it at all.

Another reason not to use no-reply@

A story from someone handling support at a UK company that regularly sends out transactional email with no-reply@company in the From: line.

Changes at Yahoo

Deliverability.com has a blog post from Naeem Kayani at Adknowledge about the recent Yahoo changes. They point to the reputation of the From: address as a factor. I’m not sure anyone knows what exactly Yahoo is doing, but the suggestions from Naeem are good ones.

Sending mail from unread email addresses

Some marketers, even large marketing companies, send mail from email addresses that are unread. Justin Premick posted a list of reasons this is a very, very bad idea. Be sure to read the comments, too.

What is an email address? (part one)

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 5322 – Internet Message Format, which describes all sorts of things about the structure of an email, including what’s valid to put in From: and To: headers. It’s really too liberal in what it allows an email address to look like to be terribly useful, but it does provide for one very commonly used feature – the friendly from where the name that’s displayed to the recipient is not just the email address.