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

• 商談の特定ステージ選択時に、集計項目の入力を必須化したい

  こんにちは。Zoho CRMの商談管理で以下を実現したいです。レイアウトルールでは、集計項目を条件に選択できず実現できておりません。よい方法があればご教示いただけると嬉しいです。 ■やりたいこと 商談で特定のステージに変更する場合に、特定の集計項目（同じ商談データ内の項目。以降、集計項目Aとする）を入力必須化したい。 ■概要、状況 ・集計項目Aは、別のオブジェクトで、商談に関連する月ごとの売上を集計している数値項目 ・見積を顧客に提示した際に、集計項目Aに見積金額と一致するようにデータ登録する運用をしている

• inventory based on bills and not physical stock

  Hello, I have noticed a very annoying issue with zoho books/inventory. I use composite items. If I have an sub assembly item on back order, I am unable to make up the composite item, even when I have received the goods and it is in my stock. I have to convert the PO into a BILL in order for the item to show as 'Accounting Stock'. The problem is that the supplier Invoice is not shipped with the goods, but can follow even a week later. So I have to make the bill have a 'dummy name and number' until

• Zoho Inventory. Preventing Negative Stock in Sales Orders – Best Practices?

  Dear Zoho Inventory Community, We’re a small business using Zoho Inventory with a team of sales managers. Unfortunately, some employees occasionally overlook stock levels during order processing, leading to negative inventory issues. Is there a way to

• Deluge error on updating datetime field

  Hi, while updating date-time field , i am getting this error  {"code":"INVALID_DATA","details":{"expected_data_type":"datetime","api_name":"Date_Time_1"},"message":"invalid data","status":"error"} Here is the code , i have tried leads = zoho.crm.getRecordById("Leads",

• No option for pick up in Zoho Books / Inventory but yes on commerce

  Is it planned to release soon on books/inventory?

• Update to CRM Custom Buttons: Collect Users' Location

  Hello everyone! Buttons in Zoho CRM allow you to extend the default CRM capabilities for your bespoke business needs. It provides the flexibility to connect to any third-party application to perform necessary actions. Wouldn't it be better, if those buttons

• Speed (again!)

  Same old story again: impossible to work at this "speed". Category NOTES!

• Client Script | Update - Client Script Support For Custom Buttons

  Hello everyone! We are excited to announce one of the most requested features - Client Script support for Custom Buttons. This enhancement lets you run custom logic on button actions, giving you greater flexibility and control over your user interactions.

• Cloning Module Customizations in Zoho FSM

  Hello Latha, I have two Zoho FSM accounts, each in a different data center. I would like to know if it is possible to clone the module customizations I have already completed in one account to my new account in the UAE from the backend. In other words,

• sending email with another account

  Hello there, i write there for an our costumer request. They want to send email from CRM with a different email (confirmed and added to zoho profile). For example they use account@zilium.com but with this account they want to send (not only with email

• Marketing Tip #27: Add a favicon and social preview image for your online store

  Small branding details can make a big difference in how professional your store looks online. A favicon (the tiny icon shown in browser tabs) helps customers recognize your store instantly, especially when they have multiple tabs open. A social preview

• Knowledge base: The nitty-gritty of SEO tags

  A well-optimized knowledge base with great SEO can benefit your company by allowing customers to find help articles and support resources using search engines. This enables customers to quickly and efficiently find the information they need without direct

• Zoho Social API for generating draft posts from a third-party app ?

  Hello everyone, I hope you are all well. I have a question regarding Zoho Social. I am developing an application that generates social media posts, and I would like to be able to incorporate a feature that allows saving these posts as drafts in Zoho Social.

• How to list WorkDrive folder contents using API

  I'm trying to read folder contents using a Deluge script. The code below returns {"errors":[{"id":"F6016","title":"URL Rule is not configured"}]}". I've tried using the search API and seen similar errors. I have proved that the connection works by creating

• Best practice to handle 50+ invokeurl calls in a loop without hitting the 30-second timeout?

  Hi everyone, I am working on a custom Deluge function where I have a Map containing around 50+ key-value pairs. I need to iterate through this Map using a for each loop and make a GET API call (invokeurl) for each item. The Problem: Because of the 50+

• filter on sheets mobile (iOS, iPadOS) does not work

  re-posting this as a question because reporting as a problem netted zero responses... I have this issue on every spreadsheet, whether imported or created natively in Zoho Sheets. I can use on desktop without issue: but on iOS the filter dropdowns are

• Solving the bug in Zoho Writer API for styling

  So... the Zoho Writer APIs for programatically creating a document do not respect a template's style. The result is that any document you generate via API needs to be manually, paragraph by paragraph, reformatted. That bug alone is sufficient to render

• Zoho Books' 2025 Wrapped

  Before we turn the page to a new year, it’s time to revisit the updates that made financial management simpler and more intuitive. This annual roundup brings together the most impactful features and enhancements we delivered in 2025, offering a clear

• Need to set workflow or journey wait time (time delay) in minutes, not hours

  Minimum wait time for both Campaigns workflows and Marketing Automation journeys is one hour. I need one or the other to be set to several minutes (fraction of the hour). I tried to solve this by entering a fraction but the wait time data type is an integer

• All new Address Field in Zoho CRM: maintain structured and accurate address inputs

  Availability Update: 29 September 2025: It's currently available for all new sign-ups and for existing Zoho CRM orgs which are in the Professional edition exclusively for IN DC users. 2 March 2026: Available to users in all DCs except US and EU DC. 24

• Comments aren't visible in shared spreadsheet

  I would like to send a spreadsheet to people who can use it to help solve a problem as a one off use unique to them. They will have to enter data in the sheet. I have comments attached to some of the cells to explain the purpose of the data being collected.

• Custom button for list page

  Why is my 'List Page - Bulk Action Menu' button in the Packages module not autopopulating the List argument with selected record IDs?

• Ask the Experts - Live Q&A webinar

  Hello Community, We’re excited to host our very first Ask the Experts session! Join us on 7 April 2026 from 11 a.m. to 12 p.m. (IST) for this live webinar Q&A session, where you will have an opportunity to connect directly with our product experts, gain

• can't see contact's last activity when in list view

  A contact has past activities recorded in their name. When I go to list view, no Last Activity is displaying. How do i fix this?

• Designing Multi-Step Workflow System in Zoho Creator + Deluge (Startup Build – Exploring Advanced Architecture + Partnerships)

  Hi everyone, I’m currently building a Zoho-based system as part of an early-stage startup, and I’m looking to connect with others who have experience designing more advanced workflows in Creator + Deluge. This started as a standard application, but it’s

• Bin Tracking with eBay integration

  When trying to setup bin tracking on items that are linked to eBay listings using the built-in Zoho eBay integration, I keep getting this error: "Storage Tracking cannot be enabled for items that are manually fulfiled or for serial/batch items tracked

• Have to ask: WHY is Zoho Purposefully blocking Apple Reminders?

  I just have to ask: Why is zoho purposefully blocking Apple reminders (CalDav). This is just strange... I just can't see a reason why this is done both within the Zoho calendar and mail calendar? These are both paid services. Why? This little simple feature is forcing me to leave Zoho. Our workflow depends on Reminders and after talking with an Apple engineer, they noticed theat Zoho is purposefully blocking this caldav port call. I just don't understand why. Thanks!

• Removing To or CC Addresses from Desk Ticket

  I was hoping i could find a way to remove unnecessary email addresses from tickets submitted via email. For example, a customer may email the support address AND others who are in the helpdesk notification group, in either the TO or CC address. This results

• Is it possible to make tags "required"

  We would like to be able to make the tag field a requirement for agents before they can close a ticket. This would help with monthly reporting, where a lot of tickets end up with no tag, causing manual work to go back and add the correct tag for each

• Prevent Automatic Milestone Inheritance for Newly Created Task Lists

  Hello Zoho Projects Team, We hope you are doing well. We would like to request an enhancement regarding how new task lists inherit Milestone association in Zoho Projects. Current Behavior: At the moment, when a new task list is created below an existing

• I would like to know wich person viewed the file

  I have a franchise and my Operative Manual is in WorkdriveI, the user can´t download but despite I know How many views the file had, I would like to know wich person viewed the file Is it possible? thank you

• Can I write a check in Zoho Books with no associated bill?

  This currently does not seem possible, and I have a client that desperately needs this function if I am able to convert them with Quickbooks. Thank you in advance for your reply. 

• Ordering of Teams

  Hi there, Currently, we cannot order Teams in Zoho Desk. Teams are ordered as they were created. It would be really helpful if we could customise the order of Teams. For example: We have the following Teams: Shipping Customer Service Sales Compliance

• Estimate Module - Contact Field.

  Hello Latha and Team, Is it possible to make the Contact field optional in the Estimate module? Best regards, Chethiya.

• Item with name in different languate

  Hello, is there a way to have an item with its name in different languages? For example: I sell an item in different markets and I'd like to have a Proposal and the Invoice with the Item Name in a specific language. Rino Bertolotto Zoho Specialist, STESA srl

• What is a realistic turnaround time for account review for ZeptoMail?

  On signing up it said 2-3 business days. I am on business-day 6 and have had zero contact of any kind. No follow-up questions, no approval or decline. Attempts to "leave a message" or use the "Contact Us" form have just vanished without a trace. It still

• How to keep track of bags, cans, drums of inventory?

  We buy and sell products that are packaged in bags 🛍️, cans🥫, drums🛢️, etc. with batch numbers. When we get a shipment of one of the products, how do we track we received (say) 10 cans each of 5L of a product and maybe we received 10 cans of another

• This version of app doesn't support this notecard type Error

  So this problem is happening for any notes created within the last week, as well as any note recently edited on Android. I can open them on my phone fine, but they don't open on the website version. They DO work on the desktop app version. It's just web

• PDF's Give Unsupported Type Error Message

  Many of the pdf files I add to Notebook work fine but in some cases when I try to open them on the Android App I get a message saying "Unsupported Type. Psst! You are using an older version of the app which does not support this note format. Please update

• Cliq iOS can't see shared screen

  Hello, I had this morning a video call with a colleague. She is using Cliq Desktop MacOS and wanted to share her screen with me. I'm on iPad. I noticed, while she shared her screen, I could only see her video, but not the shared screen... Does Cliq iOS is able to display shared screen, or is it somewhere else to be found ? Regards

• Next Page