15 Email Deliverability Best Practices For Gmail

• Premise: Gmail’s ecosystem is uniquely strict. With 1.8B+ users and advanced filtering systems, deliverability depends on sender reputation, subscriber engagement, and technical configuration.

• Goal: Provide a clear framework for avoiding Gmail-specific deliverability issues before they happen.

• Highlights:****Gmail’s Reputation System Is Multi-LayeredGmail analyzes engagement, complaints, list quality, sending domain/subdomain, DKIM, SPF, IP reputation, bounce patterns, content, coding, and more.

• Because signals are aggregated across domain + subdomain + IP, troubleshooting becomes difficult if fundamentals aren’t set early.

• Opt-In Quality Determines EverythingGmail strongly prefers confirmed/double opt-in, but at minimum requires explicit single opt-in.

• Users must opt into the exact message stream—not a category or parent-brand by association.

• Engagement Is Gmail’s #1 CurrencySend only to subscribers who open/click regularly.

• Define expiry thresholds:Daily senders → expect activity at least once every 30 days.

• Weekly senders → at least once every 90 days.

• No engagement for 12+ months → remove permanently (high spam-trap risk).

• List Health Matters More Than List SizeStop sending to hard bounces.

• Never purchase lists.

• Build your own subscriber base through permission-based growth.

• Respectful Email Etiquette Improves Inbox PlacementClear sender identity, relevant subject lines, and transparent link destinations help create a positive sender impression.

• Why is Gmail harder than other inbox providers?Gmail evaluates more signals (engagement, domain behavior, content, coding, DNS configuration, blacklist status) and applies them at a user-specific level. It rewards high quality and punishes inconsistencies quickly.
• What’s the single biggest deliverability driver for Gmail?Engagement. Highly engaged users → inbox. Low engagement → promotions or spam.
• Why is double opt-in recommended?It ensures clean lists, reduces spam complaints, and prevents Gmail from lowering your domain reputation.
• Should I worry about the Promotions tab?No. It’s visible, frequently checked, and preferred for marketing messages. You only need Primary placement when sending highly personal or non-promotional content.
• How does Gmail handle unsubscribes and complaints?Gmail does not provide traditional feedback loops. That means unsubscribes are safer than spam complaints—make unsubscribing effortless.
• Can I use affiliate links if they’re relevant?No. Gmail associates them with historically abusive senders, which can tank your reputation.
• Why is URL shortening blocked?Many spammers use shortened URLs to hide malicious destinations. Gmail treats them as high-risk indicators.

With over 1.8 billion users, there is no debate that Gmail is a leader among email providers. Chances are you have many subscribers on your business lists with Gmail addresses, and increasing your chances of successfully reaching them is essential to your company. Understanding the filters and criteria Gmail uses to determine email validity will create improved deliverability for your communications.

Gmail uses many different algorithms to determine inbox placement as well as delivery of your messages. Those algorithms use countless points of reference such as engagement, complaints, bad addresses for a combination of sending subdomain and top domain, bounce domain and DKIM, IP address, body content, branding, source coding, etc. Therefore when you have an issue, troubleshooting can be overwhelming. For organizations in regulatory environments, these deliverability concerns extend beyond basic inbox placement to include comprehensive email archiving system challenges for compliance and auditing purposes.

Below are the top 15 email deliverability best practices you should follow in order to avoid issues to begin with when sending to Gmail.

Encourage your users to opt-in to your communications instead of checking these boxes by default. Some international regions restrict auto opt-in practices and levy fines or penalties for infractions. Keep your business compliant and do away with opt-ins by default.

Gmail strongly suggests double opt-in or confirmed opt-in when possible. However, single opt-in is a must. It is important that each subscriber opt-in to the exact message stream they are receiving. It is not enough that they opt-in for your type of message. For example: Katie opts-in to receive messages sent by JobSiteA. This does NOT mean that JobSiteB can start sending Katie messages simply because it is the same subject matter or even owned by the same parent company of JobSiteA. Katie has to explicitly opt-in to JobSiteB’s messages.**

The most important thing to remember is to send messages to subscribers who are engaged with your brand. They are opening, reading, clicking and interacting with your brand. This is especially critical for FinTech companies during the onboarding process, where building trust and engagement requires specialized strategies covered in our FinTech email onboarding optimization guide. Interacting may mean purchasing or even getting involved with the discussion depending on your business model. Develop a list hygiene process to remove nonengaged subscribers from your active sending list on a regular basis.

Do not continue to send to email addresses that no longer exist or hard bounce (SparkPost suppresses hard bounces). Do not continue to send to subscribers who have not opened or clicked in a reasonable time. This length of time really depends on your business model. A good rule of thumb is that actively engaged subscribers will open and/or click on your daily messages at least once in a 30 day time frame and at least once on your weekly messages within 90 days. Any subscriber that has not opened or clicked on your messages in the past 12 months should be permanently removed from your list as they run the risk of becoming a spam trap.

Build your subscriber list on your own rather than purchasing an email list from a third-party list vendor. Sending emails to users who haven’t requested them can generate spam complaints and cause potential harm to your sending reputation and deliverability.

Being polite and professional helps create a positive impression for your business and increases Gmail deliverability. Your business name and purpose should be clear as the sender. Google also recommends email subject lines relevant to message content and links whose purpose and destinations are clear and pertinent.

While many businesses use transactional emails as an extra promotional tool by recommending additional products, your deliverability to Gmail accounts increases if you keep marketing content out of process communications. If you employ more than one IP address, you can separate the two types of emails by IP to ensure transactional emails maintain a high sender reputation and prevent them from the spam label.

Gmail does use 3rd party blacklists (which ones are unknown) to determine inbox placement.

Gmail will block most of them if used in bulk mailings, especially bit.ly.

Make it easy for subscribers to unsubscribe from your message! Google’s one-click feature permits users to click the unsubscribe button inside the email to simplify the process and prevent a user complaint. Spam complaints are not shared back to you through feedback loops like other ISPs. Therefore it is crucial that your subscribers unsubscribe rather than reporting as spam. SparkPost deploys the list-unsubscribe header and suppresses unsubscribes.

Affiliate marketers — those who earn commissions by directing web traffic to specific sites — have been known for spamming in the past. Establishing an identification as a spam sender can affect the deliverability of all future communications from your business. For best performance, Gmail states you should avoid including affiliate marketing links as a tactic. It is also against SparkPost policy to send affiliate marketing through our system.

Authenticate with both SPF and DKIM.

Google suggests using a single IP address for all email sending to aggregate sender reputation under one label. When separating communication types with subdomains, ensure they all point to the same IP if possible.

Different subdomains can define different email streams. (Example: newsletter.example.com; deals.example.com; confirmation.example.com) Be consistent. Don't add too many as you want to develop reputation for each subdomain. However, the top level domain reputation is also important.

Ensure pointer (PTR) or reverse DNS (rDNS) records are up-to-date and correct. Adhere to standard message, HTML and international domain formats. Keep coding clean and transparent — concealing code could result in Gmail categorizing your email as spam.

Gmail ties reputation to the entire DNS configuration during warm-up. Reputation is tied to the collective SPF, DKIM, IP setup, domain, etc., so configuration must be set and locked before sending. Once complete and verified by testing, don't make changes unless prepared for another warm-up cycle.

Send to the most active subscribers first, then add lesser-engaged subscribers as volume builds over time.

Due to Gmail's folder system, messages land in additional locations beyond inbox or spam. The Promotions tab isn't a wasteland — it still generates opens and clicks for interesting brands.

Filtering happens at individual subscriber level, not bulk sender level. Train subscribers to move messages to Primary tab through expected interactions. For Primary placement, design non-promotional messages: personalize with first names, minimize images, use letter format, include only one link. Appreciate the Promotions tab — subscribers know how it works and actively check it for interested marketing content.