Creating a Gmail integration using custom connectors

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

----

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

    • Recent Topics

    • Getting Permission denied to access this portal.

      We have one user that can't login to projects even though access has been granted. This user can login to accounts.zoho.com but when login to https://projects.zoho.com/portals.do we get this error: Unauthorized login to this portal Permission denied to access this portal. Check your portal URL again. Sometimes we also get "server too busy". We have tried killing sessions (in accounts.zoho.com) and we have deleted cookies; and tried different computers and still the same problem. All others use can

    • Marketing Tip #1: Optimize item titles for SEO

      Your item title is the first thing both Google and shoppers notice. Instead of a generic “Leather Bag,” go for something detailed like “Handcrafted Leather Laptop Bag – Durable & Stylish.” This helps your items rank better in search results and instantly

    • Does Zoho Docs have a Line Number function ?

      Hi, when collaborating with coding tasks, I need an online real time share document that shows line numbers. Does Zoho's docs offer this feature ? If yes, how can I show them ? Regards, Frank

    • Setting Default Views for Custom, List and Detail Views

      Hey, Is it possible to set a default custom view, list view and detail view for a module for every user? We are onboarding a lot of non technical people that struggle with these things. Setting the views as default would really help. Btw: also setting

    • Custom function return type

      Hi, How do I create a custom deluge function in Zoho CRM that returns a string? e.g. Setup->Workflow->Custom Functions->Configure->Write own During create or edit of the function I don't see a way to change the default 'void' to anything else. Adding

    • Filter Based API request in Zoho Books using POSTMAN

      How do I GET only specified CONTACTS based on created time or modified time in Zoho Books using POSTMAN. In the api documentation, it is written we can apply filters but I need a sample request.

    • URL validation

      We use an internal intranet site which has a short DNS name which Zoho CRM will not accept.   When attempting to update the field it says "Please enter a valid URL". The URL I am trying to set is http://intranet/pm/ Our intranet is not currently setup with a full DNS name and given the amount of links using the shortname probably isn't a feasible change for us.

    • Your Incoming has been blocked and the emails will not be fetched in your Zoho account and POP Accounts Click here to get unblocked.

      When entering my account, this error is thrown at me, and I deleted a good part of my deleted messages, but I still can not unblock it, I would appreciate your help. reservas@lineasperutravel.com

    • Has anyone been experiencing slow issues?

      Dear all, I just want to ask if anyone has been experiencing slow issues with Zoho Creator in the past two weeks? I worked with the ISP to improve network quality by changing routes and upgrading bandwidth, but nothing changed. I am in Vietnam.

    • Zoho Projects Roadshows 2025 - USA

      Dear Users, After an amazing response to our roadshows in 2024, we are excited to be back for the second year in a row! Join our team of experts as they walk you through the most-used features in Zoho Projects, explore powerful automation capabilities,

    • Billing Management: #6 Usage Billing in SaaS

      Imagine a customer shuffling across multiple subscriptions, a streaming service, a music app, cloud storage, and a design tool. Each one charges a flat monthly fee, regardless of how much or how little they use. Some months, the customer barely opens

    • Is there anyone who has been experiencing issues regarding the Zoho Creator Certification Website in the past 2 weeks?

      Dear all , I just wanted to ask is there anyone who was planning on taking the Zoho Creator Developer Certification Test in the past 2 weeks and have been facing errors stating that the website is under maintennance and also not allowed to access the

    • Directly Edit, Filter, and Sort Subforms on the Details Page

      Hello everyone, As you know, subforms allow you to associate multiple line items with a single record, greatly enhancing your data organization. For example, a sales order subform neatly lists all products, their quantities, amounts, and other relevant

    • GST Slabs Redefined: Stay Compliant Using Zoho Books!

      Hello Everyone! The Government of India is rolling out new GST rates, a major reform aimed at simplifying the current tax structure starting 22 September 2025. GST will move from four slabs (5%, 12%, 18%, 28%) to two main slabs (5% and 18%), plus a special

    • Allow syncing Activities from other applications

      Marketing Automation could be a much more powerful platform if you were able to sync activities into the platform (e.g. purchase, donation, etc) outside of a user doing something on your website. I'd love it if you could sync Custom CRM Modules as activities,

    • Create static subforms in Zoho CRM: streamline data entry with pre-defined values

      Last modified on (9 July, 2025): This feature was available in early access and is currently being rolled out to customers in phases. Currently available for users in the the AU, CA, and SA DCs. It will be enabled for the remaining DCs in the next couple

    • Global Sets for Multi-Select pick lists

      When is this feature coming to Zoho CRM? It would be very useful now we have got used to having it for the normal pick lists.

    • Introducing Profile Summary: Faster Candidate Insights with Zia

      We’re excited to launch Profile Summary, a powerful new feature in Zoho Recruit that transforms how you review candidate profiles. What used to take minutes of resume scanning can now be assessed in seconds—thanks to Zia. A Quick Example Say you’re hiring

    • Integración Books para cumplir la ley Crea y Crece y Ley Antifraude (VeriFactu)

      Hola: En principio, en julio de 2025, entra en vigor la ley Crea y Crece y Ley Antifraude (VeriFactu). ¿Sabéis si Zoho va a cumplir con la ley para cumplir con la facturación electrónica conectada a Hacienda? Gracias

    • Ask the Experts #1

      Hello everyone! It’s time to transform how you manage projects. Define the processes. Automate the tasks. Streamline the workflows. Let us dive into automation in Zoho Projects — from configuring workflows and custom functions to building triggers, using

    • How to overcome Zoho Deluge's time limit?

      I have built a function according to the following scheme: pages = {1,2,3,4,5,6,7,8,9,10}; for each page in pages { entriesPerPage = zoho.crm.getRecords("Accounts",page,200); for each entry in entriesPerPage { … } } Unfortunately, we have too many entries

    • Zoho Sheet - Printing - Page Breaks and Printing Customization

      I think the title is descriptive enough in that I cannot find help documentation on a simple task of adding in page brakes for separating pages on print. Thanks

    • Checking if Creator has Change History

      Like zForms - whenever an entry was updated there's an option to attached change history to email notif. Trigger -> Successful form submission

    • Unable to create embed code for resource of workdrive using API

      Hello Team, I am trying to create embed code for a resource using workdrive api in powershell, however facing some issues with injecting data in body. Followed Doc: https://workdrive.zoho.com/apidocs/v1/filefoldersharing/shareeveryone Please help, below

    • how to use validation rules in subform

      Is it possible to use validation rules for subforms? I tried the following code: entityMap = crmAPIRequest.toMap().get("record"); sum = 0; direct_billing = entityMap.get("direct_billing_details"); response = Map(); for each i in direct_billing { if(i.get("type")

    • Adding contact role to a specific deal js sdk malfunctioning

      i was trying to add the contact role to a specific deal contact but repeatedly i am getting this error: { "code": "SUCCESS", "details": { "statusMessage": { "code": "INVALID_DATA", "details": { "expected_data_type": "jsonobject" }, "message": "body",

    • Q3 Updates from Bigin!

      Hey Biginners, Hope you’re doing great! As we approach the end of 2025, we truly hope Bigin has been a part of helping you build your dream business this year! We've been busy working behind the scenes to bring you features that make running your business

    • New Series Announcement - Ecommerce Marketing Tips

      Running an online business is more than just having a website. It’s about getting the right customers to discover you, trust you, and keep coming back. To support your growth journey, we’re launching a weekly Marketing Tips series right here on Zoho Commerce

    • Client Script | Update - Introducing Subform Events and Actions

      Are you making the most of your subforms in Zoho CRM? Do you wish you could automate subform interactions and enhance user experience effortlessly? What if you had Client APIs and events specifically designed for subforms? We are thrilled to introduce

    • {"errors":[{"id":"500","title":"Servlet execution threw an exception"}]}

      Here's the call to move a file to trash. The resource_id is accurate and the file is present. header = Map(); header.put("Accept","application/vnd.api+json"); data = Map(); data_param1 = Map(); att_param1 = Map(); att_param1.put("status",51); data_param1.put("attributes",att_param1);

    • Converting Sales Order to Invoice via API; Problem with decimal places tax

      We are having problems converting a Sales Order to an Invoice via API Call. The cause of the issue is, that the Tax value in a Sales Order is sometimes calculated with up to 16 decimal places (e.g. 0.8730000000000001). The max decimal places allowed in

    • Zoho Canvas - Custom templates for related lists

      Hi, I see that the example pages load always one of our related lists in a custom template, but I dont know how to work with that:  1) How can i make my own custom templates for related lists?  2) Where and how can i check out existing custom templates?

    • Kaizen #147 - Frequently Asked Questions on Zoho CRM Widgets

      Heya! It's Kaizen time again, folks! This week, we aim to address common queries about Zoho CRM Widgets through frequently asked questions from our developer forum. Take a quick glance at these FAQs and learn from your peers' inquiries. 1. Where can I

    • open word file in zoho writer desktop version

      "How can I open a Microsoft Word (.doc or .docx) file in Zoho Writer if I only have the file saved on my computer and Zoho Writer doesn't appear as an option when I try 'Open with'? Is there a way to directly open the .doc file in Zoho Writer?"

    • How to invite friends on other social media platforms to one of my group chats in arattai?

      Hello, I have formed chat groups in arattai. I want to invite my friends on other social media platforms like WhatsApp/ FB to one of my groups. Different friends would be invited to different groups. How to share an invite link of one of my groups to

    • Zoho PDF editor has a lot of issues.

      Zoho PDF editor needs a lot of work. It hangs and glitches a lot. Deletes annotations and clearings randomly.

    • stock

      bom/bse : stock details or price =STOCK(C14;"price") not showing issue is #N/A! kindly resolve this problem

    • Zoho sheet desktop version

      Hi Zoho team Where can I access desktop version of zoho sheets? It is important as web version is slow and requires one to be online all the time to do even basic work. If it is available, please guide me to the same.

    • ZOHO SHEETS

      Where can I access desktop version of zoho sheets? It is important to do basic work If it is available, please guide me to the same

    • Zoho Books - France

      L’équipe de Zoho France reçoit régulièrement des questions sur la conformité de ses applications de finances (Zoho Books/ Zoho Invoice) pour le marché français. Voici quelques points pour clarifier la question : Zoho Books est un logiciel de comptabilité

    • Next Page