If you’re sending mail merge campaigns in Gmail with GMass, or even a different mail merge service, there are several reasons why personalization may fail. If you find that the right values aren’t being substituted for your mail merge tags, see if any of the below reasons are the cause.

1. You sent yourself a test email, but your email address isn’t in the spreadsheet or the To field.

GMass, like many mail merge services, has a Send Test Email button.

You can enter any email address and have a test email sent to that address. If, however, your campaign is set up to merge with a Google Sheets spreadsheet, and that spreadsheet has columns that you’re using throughout your Subject and Body for personalization, and your test email address isn’t also in the spreadsheet, GMass won’t know what values to use for the mail merge. Therefore, the mail merge tags will be replaced with blank values, or fallback values if you’re using fallback syntax. This is the most common reason why personalization fails.

2. You hit the Send button instead of the GMass button.

Despite a recent usability enhancement that hides the regular Gmail Send button when you have many email addresses in the To field, there are certain situations where the Send button isn’t hidden and still gets clicked accidentally when the intention is to click the GMass button. If you do this, not only will your email not be personalized, but one single email will go to everyone in the To field, exposing your list to everyone on it.

3. You connected to a spreadsheet but used the standard merge tags of {FirstName} and {LastName} instead of the ones specific to your spreadsheet.

If you are attempting to personalize a mail merge campaign with the recipient’s first name, and you notice that some emails are personalized while others aren’t, you likely made the mistake of using {FirstName} as the merge tag when the column in your spreadsheet containing first names was not “FirstName”. When you do this, the first name personalization will work for email addresses that are Gmail Contacts where Gmail has stored the first name along with the email address, but will fail for all other email addresses.

4. You connected to a spreadsheet, scheduled a campaign, and then deleted the spreadsheet rows before the campaign was scheduled to send.

GMass never stores the data from your spreadsheet internally. Anytime GMass needs personalization data for an email address, it queries it from your Google Sheet. If you delete the spreadsheet rows or delete the entire spreadsheet itself, GMass can’t pull the personalization data for an email address.

5. You had an extra space before or after the curly bracket.

When you insert personalization tags, make sure they are inserted accurately. In most cases GMass will provide you with one-click buttons to insert your mail merge tags.

The buttons will correspond to either the columns in your Google Sheets spreadsheet or they will be the standard personalization buttons of FirstName, LastName, and EmailAddress. The buttons, however, can only be used to insert the mail merge tag into the Body. If you wish to personalize the Subject, you’ll need to copy/paste the tag into the Subject.


For a comprehensive guide to personalization in GMass, see the Complete Guide to Mail Merge Personalization in Gmail.

GMass uses Gmail Drafts as the storage mechanism for every mail merge campaign you send. After GMass is finished sending the mail merge campaign, it deletes the Draft, because it no longer has any use for it. If you, however, accidentally delete a campaign’s Draft before it or its auto follow-ups finish sending, then you may wish to recover the Draft.

If you’ve deleted your Draft and one of these is true…

  1. The campaign has NOT finished sending yet, because it’s scheduled to send a certain number of emails per day.
  2. The campaign HAS finished sending, but it has auto follow-ups assigned to it, and not all auto follow-ups have been sent.

…then you should attempt to recover the Draft.

If the campaign hasn’t finished sending, you will need to recover the Draft to allow the campaign to finish sending to all of your recipients.

If the campaign has auto follow-ups, you may want to recover the Draft if you wish to make changes to any of the auto follow-up settings.

If your campaign has finished sending, but still has pending auto follow-ups, but you don’t wish to make any changes to your auto follow-up settings, then you don’t need to recover the campaign’s deleted Draft.

So, how do you recover the mail merge campaign’s Draft if you accidentally deleted it?

I’m restoring the Gmail Draft for the GMass Campaign with ID 809432.
  1. Click Compose to launch a new window.
  2. Set the To field to restoredraft@gmass.co.
  3. Set the Subject to the numeric ID of the campaign whose Draft you want to restore.
  4. Hit the GMass button. Do not hit the Send button.

If successful, the Draft will be recovered, and you’ll find it under either:

  • The Gmail Drafts Label
  • The GMass Scheduled Label
  • The GMass Auto Followups Label

Wherever you find it, it’s only one Draft, and based on the state of the campaign, it may have one or more of the above Labels attached to it.

  • If the campaign has finished sending but has pending auto follow-ups, it will have just the GMass Auto Followups Label applied to it.
  • If the campaign is in the middle of sending and also has pending auto follow-ups, it will have BOTH the GMass Scheduled and the GMass Auto Followups Labels applied to it.
  • If the campaign has finished sending but does NOT have any auto follow-ups, it will have just the GMass Scheduled Label applied to it.
  • If the campaign has finished sending and does NOT have any auto follow-ups, then it won’t have any Label applied to it other than the standard Gmail Drafts Label.

What do the Gmail Labels mean?

If a Draft has the GMass Scheduled Label, that means it’s a pending mail merge campaign and emails will still be sent. If the GMass Scheduled Label is removed, the campaign will fail to send.

If a Draft has the GMass Auto Followups Label, that means the campaign has auto followups attached to it. This Label is simply for organizational purposes, so you the user, can easily see which campaigns still have pending auto followups. Whether this Label is applied to the Draft or not has no bearing on whether the auto follow-ups send or not.

I don’t use GMass, I deleted an important Gmail Draft, and I want to recover it

If the Gmail Draft you deleted has nothing to do with GMass, and you still want to recover it, try following the tricks in this awesome article.


You can now pay for GMass, the ultimate Gmail mail merge tool, with PayPal. We recognize that many of our international users don’t have access to credit cards, and so we’re happy to formally provide a way to subscribe via PayPal.

To subscribe via PayPal, go to the GMass PayPal Subscription page.

Important points to note:

  1. Please choose the appropriate plan. If you’re subscribing an @gmail.com account, make sure to choose a “Gmail” plan. If you’re subscribing a G Suite account, make sure to choose a G Suite plan (labeled as Google Apps in the dropdown).
  2. When you subscribe with PayPal, we will have to manually activate your GMass account, so please be patient after you subscribe.
  3. When you’re taken to the PayPal page, the page will note payment to Silicomm Corporation. That is one of the companies involved in the development of GMass.

When sending mail merge campaigns in Gmail with GMass, you can already suppress a list of addresses that belong to a prior campaign. Here is a detailed guide on using Suppression Lists in GMass. Additionally, if you’re using the GMass unsubscribe link, then GMass is already suppressing anyone on your Unsubscribe List.

You may, however, want to use a Google Sheets spreadsheet as the source of a suppression list, such that you can add new email addresses to just the spreadsheet, and have all of your future mail merge campaigns automatically suppress any email address that is on the spreadsheet.

To accomplish this, you have to set up a spreadsheet to hold the email addresses, and then create a container email campaign that will continuously update itself with the email addresses in the spreadsheet. You can do this with a combination of our mail merge and Google Sheets integration, the recurring campaigns feature, and the option to “Just create Drafts”.

Step-by-step guide:

  1. Create your suppression spreadsheet in Google Sheets. You really only need one column. In this example, the column is simply “email”.
  2. Use GMass to connect to the spreadsheet.
  3. After the Compose window appears, set the Subject to something like “Dynamic Suppression List”. In the GMass Settings in the Compose window, set the campaign to Repeat daily and set it to Just create Drafts. That will ensure that no emails are actually sent. Click the GMass button to start the creation of your dynamic suppression campaign.

Now, every day, the campaign that you just created, called “Dynamic Suppression List” will be updated with any new addresses from your Google Sheets spreadsheet. No emails will actually be sent, but Drafts will be created, which you can delete if you want to keep your Gmail account clean.

You can then use this campaign as the Suppression List for your future email campaigns, by selecting it in the Suppress option under Settings.

Important note about timing:

The suppression campaign will only be updated once every 24 hours, since that’s how often the campaign will run and pick up new addresses added to the spreadsheet. Therefore it is possible that if you send a campaign and use that campaign as a Suppression List, it may not suppress addresses that were added to the spreadsheet in the last 24 hours. In the future, GMass will be enhancing the recurring campaigns feature to be able to run hourly, in addition to daily, at which point any Suppression Lists connected dynamically to a spreadsheet in this fashion will update every hour.

It might seem strange that 18 months after I launched GMass I’m writing a post about how to create a GMass account, but with our ever-growing user base, we find that people are sometimes confused about which of their Gmail accounts have GMass accounts versus which are just “aliased” to a Gmail account that has a GMass account. So let’s clear up the confusion.

To create a GMass account:

1. Install the GMass Chrome extension

You can install the extension either from the GMass website or from the Chrome Web store. To install it from our website, just go to www.gmass.co and click on any of the big ADD GMASS TO GMAIL buttons.

Remember to use Chrome. To install it from the Chrome Web Store, go here and click on the ADD TO CHROME button in the upper-right.

2. Connect your Gmail account to GMass

Log into the Gmail account for which you want to use GMass. When you login to Gmail, click any GMass button, and you’ll be prompted to link your Gmail account to GMass.

This is actually the step that creates your GMass account. Simply installing the GMass extension doesn’t create a GMass account. It only makes the buttons appear in your Gmail account.

If you want to bypass the step of logging into Gmail and clicking on the GMass popup, you can also directly link your Gmail account to GMass (just log in to Gmail), which will instantly create a GMass account. Just make sure you install the GMass extension at some point as well.

Items to note:

  1. If you login to a different Gmail account that you own, and the GMass buttons show up, that does not mean that you have a GMass account for that Gmail address. You can easily create one though, by clicking any GMass button, and following the prompts to link that new Gmail account to GMass.
  2. Many people use various aliases within a single Gmail account. For example, if your Gmail account is johnsmith@gmail.com, you may have an alias address of johnsmith@company.com set up inside your johnsmith@gmail.com account. In this case, as far as GMass is concerned, you need only create a GMass account for johnsmith@gmail.com, since that is the actual Google account GMass is connecting to. You will then be able to use GMass to send from either johnsmith@gmail.com or johnsmith@company.com. Now, if johnsmith@company.com is also a G Suite account, you may additionally want to create a separate GMass account for johnsmith@company.com. Make sure you have the GMass extension installed, and then log out of any other Gmail accounts and then log in directly to the johnsmith@company.com G Suite account.

We’ve just deployed an enhancement to our mail merge tool such that you can easily view a campaign’s content while viewing a Campaign Report, and similarly, you can now easily view a Campaign Report while viewing a campaign’s content. Be sure to reload Gmail in Chrome (and clear your cache) to get the update.

While viewing a Campaign Report in the GMass Reports –> [CAMPAIGNS] Label, a link will appear at the top of your Gmail window to the campaign content.

Similarly, when viewing the campaigns content in the GMass Reports –> Sent Copies Label, a link will appear to the campaign’s report.

You can continuously toggle between the report and the campaign!

If you suddenly find that the GMass button has disappeared from your Gmail interface, here are a few steps to take to resolve the issue:

  1. Make sure the GMass extension is enabled in Chrome. Go to chrome://extensions (copy/paste that into your address bar) and look for GMass in the list of extensions and make sure there’s a checkmark next to it, indicating that it’s enabled. You have to install the extension on each computer that you wish to use GMass. The installation of the extension is tied to an individual computer, not an individual Gmail account.

    Make sure GMass is enabled in your list of Chrome extensions.
  2. Check to see that the GMass icon shows to the right of the address bar in Chrome.

    Ensure the GMass icon shows to the right of the Chrome address bar.
  3. Try reloading Gmail again. Every time you reload Gmail, your browser will attempt to fetch the GMass buttons from our server. If there was a connection issue the last time you loaded Gmail, the buttons may not have loaded.
  4. Shut down all of Chrome, by making sure all Chrome windows are closed, and that Chrome is not an active running process anymore. Then relaunch Chrome and reload Gmail. Sometimes Chrome doesn’t properly load an extension and needs to be started from scratch in order for it to recognize a new browser extension.
  5. Check for conflicting extensions. If the red GMass buttons appear to the right of the Gmail Search field, but the GMass button doesn’t appear when you Compose a new email, that’s a sign of a conflicting browser extension.
    Do you have a conflicting Chrome extension installed?

    Go to chrome://extensions and see what might be conflicting with GMass. You may have to conduct some trial and error by disabling one extension at a time, reloading Gmail, seeing if that fixes it, and if not, re-enable that one, and disable a different one, and repeat.

  6. If you use multiple Chrome identities, make sure the GMass extension is enabled for the particular Chrome identity you’re currently signed onto. In certain cases, we’ve seen that browsers that have “Extension sync” turned on have trouble, so try turning off “Extension sync”.
  7. If you’re located outside of the United States, ensure you are able to access these websites: www.gmass.co and www.inboxsdk.com. These are the two sites that Gmail accesses behind the scenes in order to display the GMass buttons.
  8. Sometimes the extension can become corrupted. Try a) removing the GMass extension entirely by going to chrome://extensions, and clicking the Trash icon next to GMass, b) reloading Gmail, c) re-installing the extension from our homepage, and then d) reloading Gmail again.
  9. If you’re technically inclined, open up the Chrome Developer Tools console, and monitor the activity under the Console and Network tabs as you load Gmail. Filter the Network log by the word “gmass”. The browser connects to the GMass server every time you reload Gmail. Determine if there are any errors while connecting to the GMass server.

    Chrome Developer Tools
    Use Chrome Developer Tools to determine what’s happening when Chrome connects to the GMass server.
  10. Check to see whether your network is using a proxy, by going to chrome://settings and going to Advanced settings. A proxy can interfere with GMass’s ability to function because the proxy isn’t granting the GMass Chrome extension the same privileges as the GMass server would. Opening the proxy settings will open a separate window that is different on Windows vs Apple machines.
    Chrome Proxy Settings
    Check to see if the browser is connecting directly to sites or using a proxy.

    In the example below, the browser is attempting to connect to the GMass server via a proxy, but the proxy is being blocked by the proxy’s CORS policy.

    GMass Proxy Issue
    An example where GMass fails due to a proxy server.

    If a proxy is interfering with GMass, try adding a proxy exception for GMass.

    Add a proxy exception for gmass.co. This example shows how you would do it on a Mac.

Still not fixed?

If these steps don’t resolve the issue, please contact our Support team and include:

  1. A screenshot of entire your Gmail interface, showing the search bar and a blank Compose window
  2. A screenshot of your extensions listing under chrome://extensions

If we still can’t determine the cause of the missing GMass buttons, we will schedule a remote screenshare session with you to resolve the issue live. We use GoToMyAssistant to conduct screenshare sessions.

If you’ve subscribed to a GMass Team Plan, we’ve just launched several Team Plan Management features. You can now:

  1. Get a report of all accounts that are part of your Team Plan.
  2. Add accounts to your Team Plan, even if the accounts aren’t of your domain. Meaning, you can add @gmail.com accounts to your Team Plan.
  3. Set your preference for whether new accounts @ your domain should be automatically added to your Team Plan or not. By default, Team Plans start with the “auto join” setting on.

To see which accounts are part of your Team Plan:

  1. Click Compose to launch a new window.
  2. Set the To field to team@gmass.co.
  3. Set the Subject to “view”.
  4. Hit the GMass button. Do not hit the Send button.

To add accounts to your Team Plan:

  1. Click Compose to launch a new window.
  2. Set the To field to team@gmass.co.
  3. Set the Subject to “add”.
  4. Set the Message to the list of accounts you wish to add to your Team Plan, one per line.
  5. Hit the GMass button. Do not hit the Send button.

To remove accounts from your Team Plan:

  1. Click Compose to launch a new window.
  2. Set the To field to team@gmass.co.
  3. Set the Subject to “remove”.
  4. Set the Message to the list of accounts you wish to remove from your Team Plan, one per line.
  5. Hit the GMass button. Do not hit the Send button.

To change the leader of your Team Plan:

Transferring the team leader to a new person will transfer the Team Plan subscription to the new address. That new address will become the billing contact on the subscription and will assume the powers of managing the team. The current team leader will become a member of the team under the new owner.

In this example, I’m logged in as ajay@wordzen.com, and I’m the team leader of a Team subscription. I am transferring the power of the team leader to meredith@wordzen.com. meredith@wordzen.com will now own the subscription and be in charge of managing the team. ajay@wordzen will become a team member under meredith@wordzen.com.
  1. Click Compose to launch a new window.
  2. Set the To field to transfer@gmass.co.
  3. Set the Subject to the email address of the account that should be the new team leader.
  4. Leave the Message blank.
  5. Hit the GMass button. Do not hit the Send button.

To set your “auto join” preferences for your Team Plan:

  1. Click Compose to launch a new window.
  2. Set the To field to team@gmass.co.
  3. Set the Subject to “auto join on” or “auto join off”.
  4. Hit the GMass button. Do not hit the Send button.

If you have team members, whether internal or external to your organization, with whom you would like to share your GMass Campaign-level Reports, you can now do that. By sharing reports with others, every time a report is updated under your GMass Reports –> [CAMPAIGNS] Label, each person with whom you are sharing will get the same updated report in his/her account.

To share your campaign reports:

In this example, I am sharing my campaign reports with john@wordzen.com.
  1. Click Compose to launch a new window.
  2. Set the To field to share@gmass.co.
  3. Set the Subject to the email address of the account with whom you wish to share your reports. My email address is ajay@wordzen.com and I want to share my reports with john@wordzen.com, so I would set the Subject to john@wordzen.com.
  4. Hit the GMass button. Do not hit the Send button.

To revoke access to your campaign reports:

Follow the same procedure as above except set the To field to revoke@gmass.co.

Frequently Asked Questions:

Q: Does sharing my reports with another user give them any other access to my Gmail account?

A: No. Sharing your reports only sends a copy of your campaign-level reports to them. People you share with cannot see anything in your Gmail account, nor can they send GMass campaigns on your behalf.

Q: Can I share my reports with people who don’t use Gmail?

A: No. You can only share reports with existing GMass users, and all GMass users obviously have Gmail accounts.

Q: Can I share my reports with people who aren’t paying GMass subscribers?

A: Yes. You can share reports with any other GMass users, whether they have free accounts or paid accounts.

Q: How can I see everyone I’m currently sharing reports with?

A: If you’re sharing reports, then each campaign report in GMass Reports –> [CAMPAIGNS] will have a section at the bottom detailing with whom the report is being shared.


After you’ve launched a campaign, you may wish to edit it either before it actually sends or perhaps in between batches of sends.

To edit a mail merge campaign:

  1. Find the campaign under the GMass Scheduled Label.
  2. Open up the Draft for the campaign.
  3. From here, you can edit any aspect of the campaign, including the Subject, Message, or any of the campaign settings under the GMass Settings arrow, like Open Tracking, Click Tracking, the send time, and auto follow-up settings.
  4. After you’re done making changes, click the green SAVE Changes button. Alternately, you can also click the main GMass button. Both have the same effect.

If you can’t find the campaign under the GMass Scheduled Label, that means it has already finished sending. However, it is possible that the campaign’s associated auto follow-up emails have NOT finished sending. If you wish to modify the auto follow-up settings for a campaign but the original message for the campaign has already finished sending, you can also edit the campaign’s settings under the GMass Auto Follow-ups Label.

Frequently Asked Questions

Q: I see the Draft for my campaign in both the “GMass Scheduled” Label and the “GMass Auto Follow-ups” Label. Does it matter from where I make changes to the campaign?

A: No, it does not. You can make changes to your campaign from either Label. GMass stores a campaign’s data in a Draft, and you can make changes to the campaign wherever you find the Draft. Based on the type of campaign, that may be the GMass Scheduled Label or the GMass Auto Follow-ups Label. You can also find the Draft just in the Drafts folder of Gmail.

Q: Can I change the spreadsheet that is associated with a campaign?

A: No, you cannot. If you want to do this, you’ll need to cancel the campaign first, and create a new campaign.

Q: If I connect to a spreadsheet and then schedule a campaign, and then later on, I add email addresses to the spreadsheet before the campaign sends, will the new addresses be sent to?

A: No, for a regular non-repeating campaign, and yes, for a campaign that repeats daily. When you connect to the spreadsheet, GMass pulls the recipient list at that time, and for a non-repeating campaign, even if you schedule the campaign to send later, it will still only send to the recipients it initially pulled. However, the rest of the data, used for personalization, is pulled only at the time of sending. So, for example, if you connect to a spreadsheet with 10 rows of email addresses, and you schedule the campaign to send tomorrow, and then before tomorrow, you change the value of a FirstName cell from “John” to “Jon”, then Jon is the value that will be used for personalization.

But, if you add 2 more rows to the campaign before the campaign is sent, those 2 rows will still be ignored. However, if you use the recurring campaign feature with Google Sheets, the the two new rows will be sent to when the campaign runs next. A campaign connected to a Google Sheet that is set to repeat daily will pull the new addresses from the spreadsheet at the time of sending.

Q: I accidentally deleted the Draft associated with my campaign. Can I still make changes?

If you deleted the Draft associated with a campaign, that accomplishes the same thing as canceling a campaign. Meaning, the campaign will cease sending emails. It will not, however, cease sending auto follow-up emails to anyone that has already received the campaign. Therefore, if you accidentally delete the Draft, you will no longer have a means to edit the campaigns auto follow-up settings, and auto follow-up emails may still go out. You can, however, restore a deleted Draft.

Q: I made changes to my campaign while it was sending. Will the new changes take effect immediately?

Yes, almost. If you edit a campaign while it is sending, GMass will notice that you’ve made a change. It will pause your campaign for a few seconds, pick up the new settings, and resume sending automatically. Note that a few emails may still send with the old settings after you’ve made your changes, but no more than 50 should send before the changes are picked up.