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Email Deliverability: Best Practices & Tips
Email Deliverability: Best Practices & Tips

This guide provides best practices for adhering to the latest email authentication standards, including DMARC, DKIM, and SPF.

Updated over a week ago

Email providers are strengthening their authentication protocols to enhance security against phishing and spoofing threats. As of February 2024, email senders must adhere to the latest authentication standards to ensure robust protection. These standards encompass DMARC, DKIM, and SPF. This collective approach aims to fortify the integrity of email communications, providing a more secure and trustworthy experience for both you and your recipients. In this guide, we provide best practices on increasing your email reputation and deliverability.


1. Know the Difference Between a "Free" and a Workspace Email Account

  • With Gmail, free accounts are limited to 500 emails in a 24-hour period, and a maximum of 100 addresses per email

  • Google Workspace accounts (custom domains) are limited to 2,000 emails in a 24-hour period (note, this is per email, so if you have a team of 5 people, your combined limit is 10,000).

2. Perfect Your Opt-in Process

  • Send emails to people who want them, opt-outs can lead to filtering (preventing your emails from reaching their destination) very quickly

  • Gmail may not deliver messages from senders whose messages are frequently marked as spam and fall under a “clear spam rate threshold” of 0.3% of messages sent.

3. Have Clean Subject Lines

  • Create an engaging subject line that invites your prospects to read your email. Keep your Subject Line and Preview Text (a brief description of what's in your email, shown as a preview in the inbox of most major email clients next to the subject line) under 65 characters to ensure that they fit no matter what browser, email client, or device is used.

  • Do not use ALL CAPS, as this may automatically flag your email as spam by the email client.

  • Exercise caution with punctuation, avoiding the use of multiple exclamation marks. This not only risks alienating prospects, as it may come across as shouting, but some email clients may also automatically divert such emails to the spam folder.

  • Though we encourage the use of emojis in the body of an email, don’t use it in the subject line, they aren’t supported by most email clients. Your contact may see a ☐ character instead.

  • AVOID Using phrases like “FREE,” “Risk Free,” etc., which may lead to filtering

4. Understand Your Email Sender Reputation

  • Email Sender Reputation (ESR): is a measure of trustworthiness associated with a sender's domain or IP address. It's based on factors like email history, recipient engagement, and adherence to authentication protocols. A good reputation ensures emails reach inboxes, while a poor one can lead to spam filtering or non-delivery.

  • There are myriad services that will show you your reputation, and help you improve it! An email warm-up service is highly-encouraged.

  • ESR affects your throughput: the rate at which emails are sent or received by an email server or service within a specific timeframe, typically measured in emails per hour or emails per day. Efficient throughput ensures timely delivery and receipt of emails, while insufficient throughput may result in delays or email delivery failures.

  • To maintain good ESR and throughput, it's crucial to use the correct email address, avoid sending spam, create engaging emails without resorting to click-bait. Additionally, refrain from overusing HTML in emails to ensure they are perceived as valuable content rather than generic marketing material.

5. Use Domain Authentication on Bonzo

  • Domain authentication verifies the legitimacy of an email sender's domain to prevent malicious activities like phishing. It enhances email security and deliverability by confirming the sender's authenticity through protocols like SPF, DKIM, and DMARC (definitions provided below).

  • Domain authentication is essential for verifying the legitimacy of email senders and protecting against phishing. It enhances email security, improves deliverability, and fosters trust between senders and recipients.

  • Please see separate Domain Authentication article or contact Bonzo Support for instructions on how to authenticate your domain with Bonzo.


Helpful Definitions

DMARC: Domain-based Message Authentication, Reporting, and Conformance is an email validation system designed to identify and thwart email spoofing, a technique commonly employed in phishing and email spam. This system plays a crucial role in countering deceptive practices by detecting emails with falsified sender addresses, aiming to create a barrier against fraudulent messages that masquerade as legitimate communications from reputable organizations.

Learn more about DMARC - https://dmarc.org/overview/

DKIM: DomainKeys Identified Mail is a protocol, similar to DMARC, that allows an organization to take responsibility for transmitting a message by signing it in a way that mailbox providers can verify.

Lean more about DKIM - https://www.dkim.org/

SPF: Sender Policy Framework serves as an email authentication method that aids in the recognition of authorized mail servers for a specific domain. This technique enables Internet Service Providers (ISPs) to distinguish emails sent by potential spoofers, scammers, or phishers attempting to distribute malicious content under the guise of a company or brand's domain.

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By implementing these best practices, you can fortify the integrity of your communications, ensuring a more secure and trustworthy experience for you and your recipients.

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