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

• Possible to connect Zoho CRM's Sandbox with Zoho Creator's Sandbox?

  We are making some big changes on our CRM so we are testing it out in CRM's Sandbox. We also have a Zoho Creator app that we need to test. Is it possible to connect Zoho CRM's Sandbox to Zoho Creator's Sandbox so that I can perform those tests?

• I Need Help Verifying Ownership of My Zoho Help Desk on Google Search Console

  I added my Zoho desk portal to Google Search Console, but since i do not have access to the html code of my theme, i could not verify ownership of my portal on Google search console. I want you to help me place the html code given to me from Google search

• Timeline Tracker

  Hi Team, I am currently using Zoho Creator – Blueprint Workflows, and I would like to know if there is a way to track a timeline of the approval process within a Blueprint. Specifically, I am looking for details such as: Who submitted the record Who clicked

• Primary / Other Billing Contacts

  If you add an additional contact to a Zoho Billing Customer record, and then mark this new contact as the primary contact, will both the new primary and old primary still receive notifications? Can you stop notifications from going to the additional contacts

• Missing Import Options

  Hello, do I miss something or is there no space import option inside of this application? In ClickUp, you can import from every common application. We don't want to go through every page and export them one by one. That wastes time. We want to centralize

• CRM x WorkDrive: File storage for new CRM signups is now powered by WorkDrive

  Availability Editions: All DCs: All Release plan: Released for new signups in all DCs. It will be enabled for existing users in a phased manner in the upcoming months. Help documentation: Documents in Zoho CRM Manage folders in Documents tab Manage files

• Is it possible to enforce a single default task for all users in a Zoho Projects ?

  In Zoho Projects, the Tasks module provides multiple views, including List, Gantt, and Kanban. Additionally, users can create and switch to their own custom views. During project review meetings, this flexibility creates confusion because different users

• [Free Webinar] Zoho Creator webinars - Learning Table and Creator Tech Connect Series in 2026

  Hello everyone, Wishing you all a wonderful new year! May 2026 and the years ahead bring more opportunities, growth, and learning your way 🙂 We’re excited to kick off the 2026 edition of the Learning Table Series and Creator Tech Connect Series ! Learning

• Reply and react to comments

  Hi everyone! We're excited to bring to you a couple of new features that'll make your sprint process simpler. A cloud application brings with it an array of social media features that can be efficiently used in your organizational setup. As an agile scrum

• Restrict Users access to login into CRM?

  I’m wanting my employees to be able to utilize the Zoho CRM Lookup field within Zoho Forms. For them to use lookup field in Zoho Forms it is my understanding that they need to be licensed for Forms and the CRM. However, I don’t want them to be able to

• Module Customisation - Lookup function not available

  Good evening, Within my business, I can have multiple customers, who have multiple mobile assets. When I set these assets up, I enter information such as vehicle registration, Vehicle identification number (VIN), Unit number, YOM, in addition to others.

• zoho click, and nord VPN

  Unfortunately, we've been having problems with Zoho Click, where essentially the line cuts off after about a minute's worth of conversation every time we are on VPN. Is there a way we can change this within the settings so it does not cut the line off

• Zoho Calender

  a) does the clanender in zoho project allow you to see the name of the event in the celnder view, it currently says either "Task (1) or "Milestoen (1)" b) Alternatively does the calender in Zoho project integrate with zoho calender?

• Matching ZOHO Payments in Banking

  Our company has recently integrated ZOHO Payments into our system. This seemed really convenient at first because our customers could pay their account balance by clicking on a link imbedded in the emailed invoice. Unfortunately, we can't figure out how

• Team Gamification

  Would love to motivate, engage and encourage our team with our social media posts. Would like to include Gamification features of Social Media in Zoho Social or Marketing Automation. And also bring in Social Advocacy tools/tracking/management to these,

• Power up your Kiosk Studio with Real-Time Data Capture, Client Scripts & More!

  Hello Everyone, We’re thrilled to announce a powerful set of enhancements to Kiosk Studio in Zoho CRM. These new updates give you more flexibility, faster record handling, and real-time data capture, making your Kiosk flows smarter and more efficient

• New Enhancements to Zoho CRM and Zoho Creator Integration

  Hello Everyone, We’ve rolled out enhancements to the Zoho Creator and Zoho CRM integration to align with recent updates made to the Zoho Creator platform. With enhancements to both the UI and functionality, This update also tightens access control by

• Work Type - Limitation

  Hello, I'm setting up work types and have noticed, a limitation on the parts area to 10 lines. Can this be increased to 20 or greater? In addition to this, when I attempt to add the work type to a work order, the correct labour hours doesn't flow through.

• 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

• Turning the page for Zoho SalesIQ: 2025 to 2026

  As we wrap up 2025, we would like to take a moment to reflect on what we set out to achieve this year, what we’ve delivered, and where we’re headed next. What we focused on in 2025 This year was all about strengthening the core of engagement and AI, making

• Stage-probability mapping feature in custom module

  Hi, I'm building a custom module for manage projects. I would like to implement the stage-probability feature that Potentials has. Is this possible?

• Temporary Outage in Zoho Cliq Affecting US Users – July 23, 2025

  We experienced a service disruption in Zoho Cliq that impacted core functionality for users in the US region. The issue occurred between Jul 23, 2025, 06:54:00 PM IST and 07:13:13 PM IST, lasting approximately 19 minutes. To restore service stability,

• Why Sharing Rules do Not support relative date comparison???

  I am creating a Sharing Rule and simply want to share where "Last Day of Coverage" (Date field) is Greater than TODAY (Starting Tomorrow). However, sharing rules don't have the option to compare a date field to a relative date (like today), only to Static

• Zoho Cliq not working on airplanes

  Hi, My team and I have been having this constant issue of cliq not working when connected to an airplane's wifi. Is there a reason for this? We have tried on different Airlines and it doesn't work on any of them. We need assistance here since we are constantly

• Problem with Workdrive folders

  I'm having a problem a problem accessing files in a Zoho work drive folder when using the Zoho writer app. The problem folder appears grayed out in the Zoho work drive window in both the online and writer application. However I can open the folder in

• Multi-currency and Products

  One of the main reasons I have gone down the Zoho route is because I need multi-currency support.  However, I find that products can only be priced in the home currency, We sell to the US and UK.  However, we maintain different price lists for each. 

• Create an Eye-Catching Announcement Widget for Your Help Center

  Hello Everyone! In this week’s edition, let’s explore how to keep your customers updated with exciting news in the Help Center. See how ZylkerMobile wowed their customers by bringing updates right to their portal. ZylkerMobile, the renowned brand for

• Send Whatsapp with API including custom placeholders

  Is is possible to initiate a session on whatsapp IM channel with a template that includes params (placeholders) that are passed on the API call? This is very usefull to send a Utility message for a transactional notification including an order number

• Customer Management: #6 Common Mistakes in Customer Handling

  Managing customers doesn't usually fall apart overnight. More often, slight gaps in the process slowly become bigger problems. Incidents like missed follow-ups, billing confusion, and unhappy customers will lead to revenue loss. Many businesses don't

• Zoho Desk iOS app update: UI enhancement of picklist and multi picklist fields

  Hello everyone! We have enhanced the UI of the picklist and multiselect picklist fields on the Zoho Desk iOS app to provide a more refined, efficient, and user-friendly experience. We have now supported an option to Search within the picklist and multiselect

• Zoho Desk iOS app update: Revamped scribbles with Apple pencil kit

  Hello everyone! We’re excited to introduce a revamped Scribble experience, rebuilt from the ground up using Apple PencilKit for smooth strokes, proper scaling, and seamless image uploads. Please update the app to the latest version directly from the App

• Zoho Desk Android app update: Norwegian language support

  Hello everyone! In the most recent Android version of the Zoho Desk app update, we have brought in support to access the app in Norwegian language. We have introduced the Norwegian language on the IM module of the Zoho Desk app as well. Please update

• Field Description is very small

  Hello, The field Description in the activity is very small. Why don't try open a new window, or a bigger popup, or increase the width of the "popup".  Example:

• Function #53: Transaction Level Profitability for Invoices

  Hello everyone, and welcome back to our series! We have previously provided custom functions for calculating the profitability of a quote and a sales order. There may be instances where the invoice may differ from its corresponding quote or sales order.

• Payment Vouchers

  Is there any Payment Vouchers in Zoho? How can we create payment for non-trade vendors, i.e. professional fees, rent, and payment to commissioner income tax?

• API in E-Invoice/GST portal

  Hi, Do I have to change the api in gst/e-invoice portal as I use zoho e books for my e-invoicing. If yes, please confirm the process.

• When I click on PDF/PRINT it makes the invoice half size

  When I click PDF / Print for my invoice in Zoho Books, the generated PDF appears at half size — everything is scaled down, including the logo, text, and layout. The content does not fill the page as it should. Could someone advise what causes Zoho Books

• Search by contain letter in a column

  Hello, everyone I need a filter function that searches by letter in a cell, and it should be a macro. To clarify further, if I have a column with several names and I chose a search cell and what I want is search by a single letter, for example, "a" then

• Enrich your contact and company details automatically using the Data Enrichment topping

  Greetings, I hope you're all doing well. We're happy to announce the latest topping we've added to Bigin: The Data Enrichment topping, powered by WebAmigo. This topping helps you automatically enhance your contact and company records in Bigin. By leveraging

• Easier onboarding for new users with stage descriptions

  Greetings, I hope all of you are doing well. We're happy to announce a recent enhancement we've made to Bigin. You can now add descriptions to the stages in your pipeline. Previously, when creating a pipeline, you could only add stages. With this update,

• Next Page