Gmail Inbox Deliverability - Prevent Gmail Spam


Gmail is a big deal for B2C email marketers. Gmail email addresses can make up 40-80% of your list and cause headaches for marketers who need to have high inbox placement to be successful.

Gmail has over 1.5 billion users, a vast email client market share, and is always innovating around the email experience while continuously improving its algorithms to determine inbox placement and delivery of your messages.

They are demanding that marketers become better at email marketing, and we at iPost agree. We understand your goal is to prevent mail to Gmail users from being blocked or sent to spam.


Let’s be clear; there are no hacks or ways around the Gmail algorithm to get into the inbox. If you are bulking, there is no Bat-Phone or person to call at Gmail and ask for help. Long gone are the days of magic and deliverability sorcery that would somehow make things better for the sender.  

You cannot game Gmail, and if you try, it will only cost you time and frustration, which could be better spent at implementing best practices to work with instead of around Gmail.


Only send mail to people who want to get messages from you. They’re less likely to report messages from your domain as spam.

If messages from your domain are often reported as spam, future messages are more likely to be delivered to the spam folder. Over time, many spam reports can lower your domain’s reputation. Learn about your domain’s reputation with Postmaster Tools.


The following tenets serve as a guidepost to having your best chance of getting and staying in the inbox at Gmail. Please be aware that you cannot just do 3 or 4 of these and think it’s enough. Many brands try to do this and then wonder why they are bulking in 6-18 months. Remember, Gmail doesn’t care that you are Fortune 100 or 100,000 when it comes to the inbox.

1: Configuration. Authentication.

First and foremost, Gmail ties your reputation to the entire DNS configuration at your organization. The reputation is connected to SPF, DKIM, Domain, and IP setup so before you start sending ANY email to Gmail, make sure you have the entire set locked and verified.

Never, ever assume that everything is set up until you certify it and do not make any changes for goodness sake.

2: IP Warm UP 

If you are new to iPost, ensure you have a proper IP Warm plan for Gmail, and other large ISP’s that you send too. This warm plan should be inclusive of all of your new IP’s. While there are many “generic” plans out there, don’t always follow them.

It is critical that the success team here at iPost understand your business so that a custom plan can be written to ensure success.

3: Email Acquisition & Opt-In Practices

While COI (confirmed opt-in) is always the gold standard and will always increase your chances of landing in the inbox, Gmail requires an SOI (single opt-in) at the minimum. iPost also recommends that you audit your acquisition practices and ensure that the sources are tracked over time for quality instead of quantity.

You must have a good grasp on what sources produce the most engaged Gmail users and be prepared to cut them loose if they don’t meet standards.

4: Engagement is key to Gmail Inbox

It goes without saying that engagement is the key to inboxing at Gmail, but you cannot look at engagement “every once in a while.” If Gmail is a BIG part of your list, you have to continually look at engagement over a period of time using a dashboard and be prepared to take proactive measures when needed.

Nothing is worse than being reactive to Gmail issues, as correcting them can take time. Engagement is vital, but monitoring is critical.

5: Proper Email List Hygiene

If tips three and four are followed, you will also understand that list hygiene, specifically to Gmail subscribers, is critical. Set engagement rules at the organizational level and once they reach thresholds, look across other channels for engagement, and then perform hygiene against those emails.

Hygiene is much more than just looking at the validity of the list, and it can involve looking at the activity of that specific email address in other lists or email programs.

6: Gmail Email Do’s and Dont’s

Here is a list of things to help even more:

Email Do’s

  1. Do monitor blacklistings.
  2. Do take advantage of the unsubscriber header. This will avoid having the subscriber mark your email as spam.
  3. Do not exceed 102K in HTML file size.
  4. Do review their postmaster tools as a refresher.
  5. Do consider publishing a DMARC record.
  6. Do use a dedicated IP address if your volume is high enough.

Email Dont’s

  1. Don’t use URL shorteners.
  2. Don’t neglect spam complaints.


Sending emails and landing in the inbox to Gmail is as tough as you make it. Follow the 6 ways to improve Gmail deliverability guidelines above and know that mitigation if things go sideways is not an instantaneous thing.

You must have patience and discipline because Gmail is forcing us to become better email marketers.