Shoot, you canceled the install. Look, we know it's scary to install new software into your browser. If you have any doubts about our integrity, please read the hundreds of 5-star reviews of GMass on the Chrome Store. Then come back, and hit that Install button again. :)

Send mass email campaigns inside Gmail and Inbox

  • Over 700 5-star reviews on the Chrome Web Store
  • Used by employees of Uber, Twitter, LinkedIn,, and even Google
Add GMass to Gmail


  • Use Gmail to send mail merge campaigns with automatic follow-up emails.
  • Connect to Google Sheets.
  • Personalize. Schedule. Track opens and clicks.
  • Create email lists based on search results.
  • Send emails as replies to the last thread with each person.
  • The killer feature: set automatic follow-up emails to be sent sequentially until you get a reply.

Mail merge with Google Sheets

Mass email based on search results

Use Gmail's powerful search feature to find messages containing recipients to whom you want to email. Then click the Build Email List button, and a Compose window will load containing the email addresses found in those messages.

Have emails sent as replies

Choose to either have emails sent as new messages or as replies to the last conversation you had with each recipient. The latter will create the impression that you manually replied and typed a message to that recipient individually, which should increase your response rate.


Gmail's Compose window

Compose your message just like any other Gmail message. Include attachments and inline images.

Test mode

Choose to only create Drafts, in case you don't want GMass to actually send emails, or if you want to see what the personalization looks like first.

Google Sheets Integration

Choose a Google Sheets spreadsheet and GMass will pull email addresses and other fields from it. (More details)


Schedule mass emails to be sent later. (More details)

Open Tracking

Turn open-tracking on or off.

Click Tracking

Turn click-tracking on or off. (More details)

Unsubscribe Link

Provide an optional unsubscribe link at the bottom of your emails. (More details)


Campaign level reports that show how many people opened, clicked, replied, and bounced. All reports are now now downloadable in CSV format. Reports show up under the "GMass Reports" Label on the left.

Email List Builder

Extract email addresses just by searching for past conversations in your account.

Automatic Follow-up Emails

Set automatic follow-up reminder emails to be sent until your recipient replies or opens. The best way possible to boost response rates. (More details)

Manual Follow-up Campaigns

Easily send follow up email campaigns to those who replied, opened, clicked, or received, or didn't reply, open, click, or receive, or any combination thereof. (More details)

Reply Management

Emails received in response to a mass email, including replies and bounces, are automatically categorized for you, preventing Inbox clutter. (More details)

Break Gmail's Sending Limits

Send email campaigns to greater than 500 (or 2,000 for G Suite users) people at a time, using our distribution technology. Send campaigns to up to 10,000 recipients, and GMass will auto-send them over multiple days so you don't violate Gmail's limits (More details)

New messages vs. Replies

Choose whether emails are sent as new messages to each recipient or as replies to your last conversation with each recipient. If you have no prior conversation with a recipient, the email will be sent as a new message. If you do have a prior conversation with the recipient, the email will be sent as a reply, and the Subject of your email campaign will be ignored, since the Subject of the last conversation will be used.


Personalize the Subject and Body with the following insertions: {FirstName} {LastName} and {EmailAddress}. If you connect to a Google Sheets spreadsheet with other columns, you can personalize to your heart's content. {Company}, {City}, {DateOfBirth}, {CouponCode}, and any other column for which you have data can be used. (Complete Personalization Guide)


If you like GMass, we hope you'll visit the Pricing page and subscribe to a paid plan. You can also use GMass for free to send 50 emails per day. If you're using GMass inside Gmail, and you attempt to send to more than 50 emails in a 24-hour period, you'll get a popup allowing you to subscribe as well.

 Frequently Asked Questions

A: You need a Gmail or G Suite account and the Chrome browser.

A: Click "Compose" in Gmail. Enter a few email addresses in the To field. Put in a Subject and Message, and hit the GMass button (instead of the normal Gmail Send button).

A: GMass is lightweight and unobtrusive. After you install GMass, you will notice four extra buttons within your Gmail interface. Three of these buttons are small square buttons to the right of the search field: the "Build Email List" button, the "Google Sheets Connect" button and the "Follow-up Campaigns" button. Secondly, when composing an email, you'll notice the GMass button along with a settings control. Lastly, you'll see some new Gmail Labels on the left where we store reports, like open and click reports.

A: Most mass email campaigns are sent as new messages, and therefore new conversations, with each recipient. The ability to send a mass email and have each individual email sent as a reply to the last conversation with each recipient, creates a far better impression with the recipient than a new message would, because the email campaign is threaded within the conversation. If there is a recipient in your list with whom you have not had a prior conversation, then a new message will be sent.

A: This option is useful if you want to test GMass’s functionality but don’t want to actually send anyone emails. For example, if you want to ensure personalization is working, this option comes in handy. You can also use the "Send Test Email" button to test personalization.

A: Absolutely. You are composing your email just as you would any other email message in Gmail. Any feature of an email that Gmail supports you can assume that GMass also supports.

A: No. GMass is meant to supplement your existing email marketing system. While traditional email marketing services can handle email campaigns to millions of recipients, GMass is meant for small-volume sends to hundreds or thousands of people. One way GMass supplements your actual email marketing system is by making it easy to follow up with everyone that replied to a campaign sent through a traditional ESP. Assuming the replies go to your Gmail account, use GMass to search for the replies, then use the “Build Email List” feature.

A: Your emails are sent from Gmail’s servers from your Gmail or Google Apps account. You’ll see all sent messages in your “Sent Mail” folder, just like you would a regular email. The benefit of this is that you get to take advantage of Gmail's sending reputation. You will likely see higher open-rates than you've ever seen before with any other email marketing system.

A: GMass itself doesn't impose any limits, but Gmail imposes a limit of 2,000 sent emails/day for trusted Google Apps users, and 500 emails/day for other users. There are other factors that determine sending limits too, such as the age and reputation of your Gmail account. GMass allows you to artificially break those limits by distributing your emails over multiple days if your campaign exceeds your account's daily limits. For detailed information on Gmail sending limits, see:

A: You can access your open-tracking, click-tracking, and unsubscribe reports by clicking on the "GMass Reports" Label on the left of the Gmail interface. Note that the "GMass Reports" label only shows after you have at least one reporting event take place, meaning at least one email open, one link click, or one unsubscribe. Note that you must click the tiny expansion arrow next to "GMass Reports" to expand and see other report categories.

A: You can search based on any number of criteria and fields, from text in the Subject and Message, to Dates sent and received, and you can even use boolean operators. Gmail has a great web page on advanced searches. See

A: Yes, as of August 2017, GMass works with the new Inbox by Google. So you can use it with classic Gmail or the new Inbox.

A: When it comes to Gmail integration, there aren’t that many alternatives. The other mass email solutions are part of a larger product, while GMass is focused on just mass email and mail merge functionality. We built GMass to be dead simple.

A: GMass was free for the first 11 months of its existence. Starting August 15, 2016, we are asking serious users to subscribe to a paid plan. You can use it for free to send up to 50 emails at a time, but if you need to send more, you will need to subscribe.

A: Absolutely not. GMass connects to Gmail's API to operate, and that requires you granting GMass access to certain parts of your account through the API. GMass staff will never see your email, and in fact, even when you use GMass to send emails, we don't store the contents of your email messages. We only store the recipient addresses and the Subject lines, so that we can provide Open and Click Reports.

 Our Story

Ajay Goel

GMass Creator

The GMass Story

GMass was born out of the frustration of its creator, Ajay Goel. While recruiting writers for his other Gmail product, Wordzen, he was disheartened by how difficult it was to communicate with all of his writer prospects at once. He simply needed to inform the five candidates that the position was of the 1099 and not W2 variety, but to his dismay, he had to find each conversation with each editor, hit Reply, and type a personalized message. Ajay has lots of experience building email products, especially mass email products. He also built JangoMail, which was acquired by a private equity group in 2013.