Creating a Gmail integration using custom connectors

Hello everyone!

Greetings from Deluge. Following up on our series aimed at exploring the capabilities of Deluge, today we'll take an in-depth look into the Deluge custom connections that can be created across Zoho services.

Deluge boasts an extensive range of over 260 built-in integrations spanning more than 35 Zoho services. These integrations streamline data access and modification with these services, from a single point in Zoho, without having to toggle between services. However, we understand that the needs of our users vary widely, and sometimes existing integrations may not cover every scenario.

That's where custom connections come in. Think of them as the Swiss Army Knife of integrations, enabling connections with hundreds of services—such as Gmail and Outlook—and seamlessly integrating them with your favorite Zoho services. With custom connections, you have the power to build your own integrations with virtually any third-party service and tailor them to meet your requirements. Moreover, since the custom connections use the OAuth 2.0 authentication mechanism, you're getting best-in-class security while integrating with third-party services.

What are connections? 

Before we dive into the details of custom connectors, let's take a glimpse at what connections are in Deluge. Connections are a means to connect your Zoho account and any third-party accounts you wish to integrate with. Once a connection is created and connected, you can use it in Deluge integration tasks or invokeURL scripts to perform REST operations on the target service from the required Zoho service. For more information, visit our Connections help doc.

  

Use case 

Assume the sales team of an organization uses Zoho CRM for managing leads, customer retention, and customer acquisition, and uses Gmail for communication purposes, like following up with potential clients via email.   While the system works as is, it's time-consuming and prone to error, so an integration between Gmail and Zoho CRM is necessary to improve efficiency.

A custom connection to your Google account will enable you to sync your Zoho CRM and Google accounts, allowing you to perform actions related to your Google account from Zoho CRM. For example, you can invoke the connection using the invokeURL task in Zoho CRM and send an email to your leads from your Gmail address.

Steps to configure the Google custom connection

Configuration video

Configuration steps

Creating Google OAuth credentials

1. Visit https://console.cloud.google.com/.
   
2. Click the dropdown and choose the required project.
   
3. Navigate to the hamburger menu on the left and click APIs and services -> Library.
   
4. You'll be taken to the API library page. Navigate to the Google Workspace section and click Gmail API.
   
5. Next, click Enable on the Gmail API product details page.
   
6. In order to use this API, you'll need to create credentials. Click CREATE CREDENTIALS.
   
7. On the Create credentials page, choose Gmail API in the Select an API dropdown and User Data under the What data will you be accessing? section. Click Next.
   
8. Next, on the OAuth consent screen, enter the App name, User support email, and Developer contact email address. Then click Save and Continue.
   
9. Next, under the Scopes section, click the ADD OR REMOVE SCOPES button.
   
10. In the Update selected scopes pane, search and select the gmail.readonly scope. Click Update, and then click Save and continue.
    
    
    
11. Now, under the OAuth Client ID section, choose Web application in the Application type dropdown. Then name your app.
    
    
    
12. Enter https://deluge.zoho.com/delugeauth/callback as the Authorized redirect URI.
    
13. Click Create and download your credentials. This Client ID and others will be required later, while creating a connection in Zoho CRM.
    
14. Navigate to the OAuth consent screen and click Add users under Test users. Enter the user's email address and click Save.
    

Creating a custom connector for Gmail

1. Now the action shifts to Zoho CRM. Navigate to crm.zoho.com -> Settings -> Connections.
   
2. Choose Custom Services and click Create Service.
   
3. On the Create Service screen, choose OAuth 2.0 as the Authentication type and Header as the Parameter.
   
4. Enter the Client ID, Client Secret, and Authorize URL generated from Google as shown in step 12 above.
   Tip: Having the Offline access type will allow your application to refresh tokens even when the user is not actively using the application.
5. Then enter https://oauth2.googleapis.com/token as the Access token URL and Refresh token URL.
   
6. Specify the necessary scopes like read and create, etc. and then click Create Service.
   
7. On the next page, click Create Connection. Give the connection name and choose the scopes. Then click Create and Connect.
   
8. Finally, authenticate the connection on the Google accounts page. Your custom connection will be created, and the two services can be integrated!
   

Now that the connection between Zoho CRM and Gmail has been established, you can use the invokeURL task to access and modify data in Gmail using the different APIs.

Sample

You can use the below code in invokeURL task to get the latest emails from Gmail.

userId = "emailaddress@gmail.com";
get_gmail = invokeurl
[
url: "https://gmail.googleapis.com/gmail/v1/users/"+userId+"/messages"
type: GET
connection : "connectionname"
];
messageID = get_gmail.get("messages").get(0).get("id");

get_gmail_withID = invokeurl
[
url: "https://gmail.googleapis.com/gmail/v1/users/"+userId+"/messages/"+messageID
type: GET
connection : "connectionname"
];

Content_of_the_mail = get_gmail_withID.get("snippet");
info "Mail Content : " + Content_of_the_mail;

gmail_values = get_gmail_withID.get("payload").get("headers");
for each headers in gmail_values
{
if ( headers.get("name") == "Subject" )
{
info "Subject of the Mail : " + headers.get("value");
}
if ( headers.get("name") == "From" )
{
info "From Address : " + headers.get("value");
}
}

References

Connections
invokeURL

----

And that's a wrap for today! We hope you found this post informative and start using custom connections to experience the full capabilities of Deluge and Zoho.

Kindly let us know if you have any questions, feedback, or suggestions in the comments, or write to us at support@zohodeluge.com!

 

Regards,

The Deluge Team

• Topic Participants

• Ashwin Vishal R

  

• Kaushal

• Anand M B

  

• Recent Topics

• Pricing Strategies: #6 Common Mistakes while Configuring Pricing

  "Why does this month's billing feel messy again?" That was the exact line Priya muttered while staring at the spreadsheet full of edited pricing, one-off discounts and mismatched subscription details. Her business was growing, but the pricing machine

• Publish to LinkedIn via API

  Hi, Is it possible to publish a job opening to LinkedIn (paid job slots) if creating a job opening via api / deluge function? Or is the user required to manually publish via the job boards process? Many Thanks Adrian

• FSM - Associating and selecting Contacts based on Service Addresses

  Hi FSM team, I've come across an FSM limitation I wanted to share for improvement. I'm currently configuring FSM for a client who provides heating system install and maintenance services. The are often sub contracted by building management companies to

• Do Unpublished Products in Shopify Sync to Zoho POS?

  Will an unpublished product in Shopify sync to Zoho POS? I would like to know how Zoho POS handles products that are in draft/unpublished status in Shopify.

• Problem in Zoho POS frontend ERP.

  We are facing some difficulties in our billing and inventory processes and require your support to resolve them at the earliest. Customer Advance Payments We receive advance payments from customers for upcoming sales. Please guide us on how to record

• How to create estimates/Invoices with sub-totals

  Every other accounting package can create estimates and invoices with Sub-totals. How can I do that in ZohoBooks?

• Categorize Items with Item Headers

  Hello customers, Did you ever want to classify items based on specific categories to help your customers understand your invoice better? With the new Item Header feature, you can easily categorize items in your invoices and estimates and give them a common title.  Item Headers are available in the Invoices, the Recurring Invoices and the Estimates module. It can be carried forward from estimates to invoices at the time of converting the estimates.  To add an item header: Go to the Estimates, Invoices

• Emails sent through Bigin are not posting in IMAP Sent folder

  I have set up my email to work from within Bigin using IMAP.  I am using IMAP so I can sync my email across multiple devices - phone / laptop / desktop / iPad / etc.  I want all my emails to populate my email client (outlook & iphone email) whether or

• Discount on the transaction level in POS

  "Is it possible to apply a discount on the total bill before tax in Zoho POS?" I want to apply a discount on the total transaction amount in Zoho POS, but the discount should be calculated before the taxes are applied. Is there an option to do this in

• Create Tasklist with Tasklist Template using API v3

  In the old API, we could mention the parameter 'task_template_id' when creating a tasklist via API to apply a tasklist template: https://www.zoho.com/projects/help/rest-api/tasklists-api.html#create-tasklist In API v3 there does not seem to be a way to

• Send Automated WhatsApp Messages and Leverage the Improved WhatsApp Templates

  Greetings, I hope all of you are doing well. We're excited to announce a major upgrade to Bigin's WhatsApp integration that brings more flexibility, interactivity, and automation to your customer messaging. WhatsApp message automation You can now use

• Jobs at multiple locations

  Hi A lot of times we have same job open at multiple locations. So I would like an option where we can create a job and choose multiple locations. Currently we have to create individual jobs for each location. If we can create one job and mention multiple

• From Zoho CRM to Paper : Design & Print Data Directly using Canvas Print View

  Hello Everyone, We are excited to announce a new addition to your Canvas in Zoho CRM - Print View. Canvas print view helps you transform your custom CRM layouts into print-ready documents, so you can bring your digital data to the physical world with

• Tag Adding Option in Kanban Card Customization Bigin CRM Mobile App

  I would like to request an option to add and display tags on Kanban cards in the Bigin CRM mobile app. This feature would make it easier to categorize deals and quickly identify priorities while working on the go.

• Empowered Custom Views: Cross-Module Criteria Now Supported in Zoho CRM

  Hello everyone, We’re excited to introduce cross-module criteria support in custom views! Custom views provide personalized perspectives on your data and that you can save for future use. You can share these views with all users or specific individuals

• Associating a Candidate to a Job Listing

  Hello, I am trying to use Zoho Forms embedded on my website for candidates to apply for a job opening. I want the form then to tie directly with zoho recruit and have the candidate be automatically inputed into Recruit as well as associated with the specific

• Associating a Candidate to a Job Listing

  Hello, I am trying to use Zoho Forms embedded on my website for candidates to apply for a job opening. I want the form then to tie directly with zoho recruit and have the candidate be automatically inputed into Recruit as well as associated with the specific

• WhatsApp Voice Message Sending Option in Bigin CRM

  I would like to request a feature that allows users to send WhatsApp voice messages directly from Bigin CRM. This would help improve communication efficiency and make it easier for teams to respond quickly to customer inquiries.

• CRM: hosting a single html file in Zoho and displaying it as a widget

  I have seen that CRM offers the option of uploading a web project to Zoho itself and displaying it as a widget in CRM. The instructions then talk about setting a development environment with Node and developing an application to upload to Zoho. But I

• How to change position button transtition of Blueprint?

  Hi Everyone, Look at my screenshoot, it is possible move the reject button to the right? I couldn't find that setting in the blueprint. Thank you.

• Multi file upload

  Hi, I just wonder if one could upload multiple files in one shot, say between one and three files, without adding multiple File Upload fields? Thanks, Alalbany

• Sorting Descending in a lookup

  I have a case number lookup on multiple forms. I need the most recent added to appear at the top of the lookup or as the list of cases grom it's too much to scroll. Is there a way to have a look up sort descending?

• Importing customer comments and multiple shipto addresses

  I am evaluating Zoho Books and have most of my data imported with two exceptions: (1) Import customer comments - in my current system I have several comments of different types, and I need to bring these into Zoho. Preferably Books customer records, but

• Auto-upload Creator Files to WorkDrive

  Hi everyone, I’m working on a workflow that uploads files from Zoho Creator to specific subfolders in Zoho WorkDrive, as illustrated in the attached diagram. My Creator application form has two multi-file upload fields, and I want—on successful form submission—to

• Asap Widget 2.0

  Where's the documentation for the new ASAP widget? https://www.zoho.com/desk/developers/asap/#introduction this one is outdated How can we dynamically navigate between different views? How can we prefill ticket forms using ASAP 2.0?

• Can the Trigger be changed?

  I'm afraid I already know the answer, but here goes... After activating a workflow (under Campaigns > Automations), Then later choosing to Edit the workflow, Can the Workflow's Trigger be changed? Currently the entire Trigger section + options are gone

• Marketer's Space: Proven tips to improve open rates – I

  Hello Marketers! Welcome back to another post in Marketer's Space! In this week's post, we'll discuss the ever-important concept of open rates. This will be a multi-part series, as we have a range of topics to cover. Open rates—which measure the percentage

• Creating Custom PDF Template from Form

  I am trying to create a custom PDF from form submissions. I have the standard subscription and it indicates that PDF forms are included. I cannot find anywhere to create PDF forms. I try to follow the instructions from here: https://help.zoho.com/portal/en/kb/forms/form-settings/pdf-settings/pdf-editor/articles/creating-your-own-pdf-template#Creating_your_template_from_the_scratch

• Important Update: Facebook Metrics Deprecation & Impact on Zoho Analytics

  Dear Zoho Analytics users, Facebook has deprecated a set of metrics from the Facebook Pages Insights API, effective November 15, 2025. As a result, these changes will affect any reports and dashboards in Zoho Analytics that rely on Facebook Pages data.

• Quick Copy Column Name

  Please add the ability to quickly copy the name of a column in a Table or Query View. When you right-click the column there should be an option to copy the name, or if you left-click the column and use the Ctrl+C keyboard shortcut it should copy the

• Conditional Field Visibility in Bigin CRM

  I would like to request support for conditional field visibility within Bigin CRM. This feature should allow administrators to configure show/hide rules for fields based on predefined criteria (e.g., field values, picklist selections, stage changes,

• Introducing Zoho MCP for Bigin

  Hello Biginners! We're excited to introduce Zoho MCP for Bigin, a completely new way of interacting with Bigin data using AI. With Zoho MCP, you can securely connect your Bigin account with popular AI agents like Claude, Cursor, Windsurf, and VS Code,

• MCP > Creator connection failing with Claude

  I'm trying to get claude to access any of my Zoho Creator apps and it keeps failing. I have enabled all tools for creator and ensured in claude settings that everything is authorised. Here is what claude says : Unfortunately, the error messages I'm receiving

• Is it possible to sync data every 5–10 minutes in Zoho Analytics (CRM or Excel imports)?

  Hello Team, I want to know if Zoho Analytics supports near real-time syncing of data from different sources. My requirements: I am importing data from Zoho CRM → Zoho Analytics I also have some datasets maintained in Excel/CSV I want both data sources

• Feature Request: Dynamic Dimension Control for zc_LoadIn Popups

  As detailed in this community discussion, Zoho Creator's zc_LoadIn parameter is a vital tool for opening components (forms, reports, or pages) in modal dialogs via HTML snippets, Notes, or Rich Text Fields. While powerful, this feature suffers from a

• Subforms in stateless forms

  I think the title says it all. We need to be able to add subforms to stateless forms. Currently the only workaround is to create a Form and delete each record upon submission of the form. I need to build an interface to update our inventory. Basically

• Text wrap column headers in reports?

  Is it possible to auto wrap column headers so that a longer multi-word header displays as two lines when the column is narrower than the width of the header title?

• What’s New in Zoho Inventory — Latest Features, Integrations & Updates | December 2025

  Zoho Inventory has evolved significantly over the past months, bringing you smarter, faster, and more connected tools to streamline your operations. Whether you’re managing multichannel sales, complex fulfillment workflows, or fast-moving stock, our newest

• Marketer’s Space - Multi-Channel Campaigns for the Biggest Shopping Week with Zoho Marketing Automation

  Hello marketers, Welcome back to another post in Marketers Space! The biggest shopping week of the year is almost here, and it’s your moment to shine without the stress. With Black Friday and Cyber Monday just around the corner, being present across email,

• Pricing Strategies: #5 Stay local, Price & Sell Global

  Arun had always dreamed of taking his handmade craft business beyond his hometown. For years, he sold locally. Most of his customers are familiar faces, in our usual currency and with the exact expectations. But one day, a traveller visited his workshop

• Next Page