什么是电子报？定义与指南

电子报是定期通过电子邮件发送给订阅者名单的出版物。

Technology and Automation

A newsletter is a recurring publication sent to a defined audience, usually by email, to share current information on a topic. In digital marketing, it runs as an ongoing series that readers subscribe to, separate from one-off promotional or transactional messages. Writing a good issue is only half the job, because Gmail tells every sender to keep the spam rate reported in Postmaster Tools below 0.3%, and it lists that limit as a requirement, not a tip. As one format inside the broader email marketing discipline, a newsletter has to clear three separate bars before it does any good: the law, the mailbox provider, and the reader.

Newsletter, Defined by Format, Not List Size

List size doesn't make an email a newsletter. Format does.

What Makes an Email a Newsletter

Library cataloging standards offer a useful anchor. In 2021, the Library of Congress approved a dedicated newsletter code for continuing resources in the MARC 21 bibliographic format, and the Library of Congress MARC proposal describes a newsletter as "a short periodical" issued by an organization, generally to its members or to a specific audience, to give current information about a topic or sphere of activity.

Three traits follow from that description. The format repeats on a schedule. It serves a defined audience. And it carries current information, so each issue has a reason to exist beyond the sender wanting attention. A single sale announcement pushed to a large list has none of those traits, no matter how many people receive it.

Newsletter vs. Email Marketing, Promotional, and Transactional Email

Email marketing is the discipline, and the newsletter is one format within it, alongside promotional campaigns and automated sequences. The distinction isn't just vocabulary. Under the U.S. CAN-SPAM Act, the label you put on a message doesn't decide how it's treated. The FTC's CAN-SPAM compliance guide classifies email by its primary purpose: a message with only commercial content has to comply fully, while a message that's purely transactional or relationship content is exempt from most provisions, although its routing information still has to be accurate.

Gmail draws a similar line. Its sender FAQ excludes transactional messages, such as password resets and reservation confirmations, from the one-click unsubscribe requirement. Mix editorial content with offers, and the newsletter isn't transactional, whatever you call it.

Why Organizations Publish Newsletters

Relationships and Subscriptions, Not Just Sales

Not every newsletter exists to close a sale. News publishers offer the clearest documented example. In a discussion of the Reuters Institute's email news findings from its Digital News Report 2022, lead author Nic Newman described email as a leading tool for building loyalty and encouraging more frequent visits, and he pointed to publishers bundling newsletters into paid subscriptions to help keep subscribers.

That's a publisher pattern, not a law of marketing. A software company or a retailer can borrow the logic and use a newsletter to keep customers informed between purchases, but the Reuters evidence doesn't measure brand newsletters, so it shouldn't be read as proof that they'll behave the same way. In practice, a newsletter usually sits inside a broader content marketing program, where it redistributes what the team already publishes and gives readers a reason to come back.

How Niche the Channel Still Is

A Pew Research Center newsletter survey of 5,153 U.S. adults, fielded Aug. 18 to 24, 2025, and published in February 2026, found that just 3% of U.S. adults name newsletters as their preferred platform for getting news. Among U.S. adults who get news from newsletters at least rarely, 62% said they don't end up reading most of the newsletters they receive.

That second number is the reader threshold in plain terms. It covers news newsletters in one country, so it isn't a benchmark for every brand. Still, it's a fair warning. Delivery and attention are different outcomes.

Permission: What the Law Requires vs. What Inboxes Expect

Ask whether a newsletter needs permission and you'll get two answers. Both are correct. One comes from the law, and the other comes from the companies that run the inboxes your subscribers actually check every morning.

CAN-SPAM's Opt-Out Model

The U.S. federal baseline is an opt-out model. The FTC guide doesn't describe a general requirement to collect consent before sending commercial email. Instead, it sets rules for the message itself: accurate header information, subject lines that don't mislead, a valid physical postal address, and a working way to opt out that you honor within 10 business days. Rules outside the U.S. differ by jurisdiction, so treat this as an American baseline rather than a global answer.

Mailbox Provider Expectations

Gmail sets a higher bar. Its Gmail email sender guidelines tell senders to make sure recipients opt in and to confirm each recipient's address before subscribing them. That's the logic behind confirmed or double opt-in: the person signs up, then verifies the address before the first issue arrives.

That leaves a gap. A sender can be fully lawful in the U.S. and still fall short of what Gmail asks for. The mailbox provider decides whether the message reaches the inbox, so for any newsletter of real size, the provider's rules rather than the statute end up defining what good practice looks like day to day.

Sender Requirements Once a Newsletter Scales

Growth changes the rules you're playing by.

The Gmail Bulk-Sender Threshold

The Gmail sender guidelines FAQ defines a bulk sender as one that sends close to 5,000 messages or more to personal Gmail accounts within 24 hours. Volume counts against the primary domain, so mail sent from a subdomain adds to the parent domain's total. Two details catch teams off guard. The status doesn't expire, so a domain that qualifies once is treated as a bulk sender permanently. And starting in November 2025, Google said it was ramping up enforcement, with noncompliant traffic facing temporary and permanent rejections.

The spam rate limit applies long before you reach that volume. Gmail's guidelines tell all senders to keep the spam rate reported in Postmaster Tools below 0.3%, and the FAQ says bulk senders above 0.3% aren't eligible for Gmail's delivery mitigation. The Yahoo Sender Hub best practices set the same 0.3% ceiling for bulk senders.

SPF, DKIM, and DMARC

Gmail and Yahoo both require bulk senders to authenticate mail with SPF and DKIM and to publish a DMARC policy. Neither demands a strict policy on day one. A DMARC record set to p=none, which only monitors results, satisfies both providers. SPF lists the servers allowed to send for your domain, DKIM attaches a cryptographic signature to each message, and DMARC tells receiving servers how to handle mail that fails those checks. Authentication proves the mail is really yours. It doesn't prove anyone wanted it, which is why a fully authenticated newsletter can still end up in spam.

One-Click Unsubscribe and RFC 8058

One-click unsubscribe lets a reader leave from the mail client's own interface, without opening a web page or confirming anything. The mechanism comes from IETF standard RFC 8058, a Standards Track document published in January 2017. It requires a List-Unsubscribe header containing one HTTPS URI, a List-Unsubscribe-Post header carrying the value List-Unsubscribe=One-Click, and a valid DKIM signature that covers both headers. A footer link alone doesn't implement it, and Gmail says a mailto link in the message body doesn't meet its one-click requirement either.

Google's own documentation gets ambiguous on this point. The sender guidelines say "marketing messages and subscribed messages must support one-click unsubscribe," while the FAQ says one-click is "required only for marketing and promotional messages." A purely editorial newsletter could land on either side, depending on which page you read. The practical answer is simple. Give every bulk newsletter one-click unsubscribe, plus the clearly visible unsubscribe link in the body that Gmail and Yahoo both require. Transactional messages remain excluded.

Unsubscribe Deadlines: Providers vs. the Law

Three deadlines apply, and they come from three different authorities.

CAN-SPAM (U.S. law): opt-out requests must be honored within 10 business days, according to the FTC.
Gmail: Google recommends fulfilling unsubscribe requests within 48 hours, and its requirements table lists requests not honored within 48 hours as a compliance issue.
Yahoo: the Sender Hub tells bulk senders to honor unsubscribes within 2 days.

The legal floor is the slowest of the three by a wide margin. Run your process to the fastest one, because a request that's still legal on day nine has already been a problem with the mailbox providers since day three.

Measuring a Newsletter Without Trusting Opens

Why an Open Isn't a Read

Open rate depends on a tracking pixel, a tiny remote image that reports back when it loads. Apple's Mail Privacy Protection privacy page says that when Protect Mail Activity is on, Mail fetches remote content in the background, whether or not the recipient engages with the message. That's Apple's documented behavior.

The consequence is an inference, not something Apple states: for those readers, a recorded open can mean the device fetched the pixel rather than that a person read the issue. Opens can still hint at broad delivery patterns. They just can't carry the weight of proving attention, and the Pew finding above, that most news newsletter readers skip most of what arrives, points in the same direction.

Metrics Tied to the Newsletter's Purpose

Start from the job the newsletter is supposed to do, then pick the evidence that job would leave behind.

Loyalty or retention: unsubscribes per send, replies, and repeat clicks from the same subscribers over time.
Traffic or education: clicks to specific pieces, measured against messages delivered.
Revenue: conversions or paid renewals from newsletter links, reported as attributed results and kept separate from claims of causal impact.
List health: the spam rate in Postmaster Tools, checked against the 0.3% limit.

Privacy rules add a second reason for caution. In France, the data protection authority CNIL adopted guidance in March 2026 that treats email tracking pixels much like cookies, requiring recipient consent when open rates are analyzed to measure and optimize campaigns while allowing narrower deliverability uses, such as pausing sends to inactive recipients. That topic overlaps with Pixel Tracking. Tracking pixels don't come up in the FTC's CAN-SPAM guide at all.

Newsletter Mistakes That Cost Deliverability

Most problems trace back to a few habits. None of them are exotic.

Relying on a footer link alone. A visible body link is required, but without the RFC 8058 headers it isn't one-click, and a mailto link doesn't satisfy Gmail.
Adding people who never opted in. Holding an address isn't the same as a request, and Gmail asks senders to confirm each address before subscribing it.
Making decisions from open rates. Subject-line tests judged on opens inherit the pixel problem, so judge them on clicks or downstream actions instead.
Treating the legal minimum as the standard. Ten business days satisfies CAN-SPAM, but it doesn't meet Gmail's 48-hour expectation or Yahoo's 2 days.
Watching the spam rate too late. Above 0.3%, Gmail bulk senders lose eligibility for mitigation.

Each habit chips away at the wider email deliverability picture. Providers assess the sender over time, so careless sends can weigh on later issues from the same domain.

Newsletter FAQs

Is a newsletter the same as email marketing?

No. The broader practice is email marketing, and a newsletter is one recurring format within it, alongside promotional campaigns and automated messages. Promotions can appear in a newsletter, and once they do, U.S. law classifies the message by its primary purpose rather than its name.

Do newsletters legally require opt-in?

Not under U.S. federal law. CAN-SPAM uses an opt-out model and doesn't set a general consent requirement. Gmail, however, tells senders to make sure recipients opt in and to confirm each address, so opt-in is the operating standard even where the law doesn't demand it. Rules elsewhere differ.

What is one-click unsubscribe, and who must implement it?

It's an unsubscribe action defined in RFC 8058 that works from inside the mail client through DKIM-signed List-Unsubscribe headers. Gmail requires it from bulk senders, and Yahoo requires a working List-Unsubscribe header that supports one-click unsubscribe, recommending the RFC 8058 method. On scope, the guidelines name marketing and subscribed messages, while Gmail's FAQ names marketing and promotional messages. Either way, transactional messages are excluded.

Does a high open rate mean subscribers read my newsletter?

Not necessarily. Apple documents that Protect Mail Activity downloads remote content in the background whether or not the recipient engages, so an open can be recorded without a read. Use clicks, replies, and outcomes tied to the newsletter's purpose.

What happens if my spam rate passes 0.3%?

Gmail tells senders to keep the Postmaster Tools spam rate below 0.3%, and its FAQ says bulk senders above that level aren't eligible for mitigation. Senders that miss Gmail's requirements may see messages rejected or delivered to spam. Yahoo sets the same 0.3% ceiling for bulk senders.

How fast must unsubscribes be processed?

CAN-SPAM allows up to 10 business days. Gmail recommends 48 hours and treats slower handling as a requirement issue, while Yahoo asks for 2 days. Build your process around 48 hours.

Related Terms

How content marketing works - the strategy that supplies most of what a newsletter distributes.
Customer retention, defined clearly - the outcome many brand newsletters are meant to support.
Permission Marketing - the practice of sending only to people who asked to hear from you.
Open Rate - the pixel-based metric that privacy features have made unreliable as proof of reading.
Pixel Tracking - the remote-image technique behind open tracking, and the focus of the consent rules mentioned above.