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

• Time Zones for Users

  I've searched for this topic, but the only answers I see are from years back. We have users all over the country. is there a way for them to set their own time zone? This is important and should be a standard setting, but I do not see how to do it.

• Showing the map along with mileage expense

  When you use the GPS to track mileage, it shows you the map of the actual path travelled. It would be very useful and practical to save that map with the mileage expense, so that when the report is created, it provides a map of each mileage expense associated

• ID:2406331

  Hello, I have sent the form (ID:2406331) but no answer after two days. This is a paid subscription, I am not allowed to use the eighth paid slot of 50GB email space anymore, only 7 are being used. Is anyone going to help me please so I can use the eighth

• Transaction Rule Matching

  Q1. Is there a method to have the Transaction Rules applied across multiple Bank Accounts? Q2. To match "contains" text in Transaction Rules, is a wildcard or regular expression required? Is it case sensitive? Would searching for "issue" in the following

• Notebook on Mac: Fuzzy fonts in list view

  Hi, I am running Notebook on Mac OS 26. Generally it works fine, and the font display in the notes themselves is crisp. However, in the notes list (left of the open note) the font of the note titles as well as first lines is noticeable fuzzy. Attached

• Trigger workflows from SLA escalations in Zoho Desk?

  Hey everyone, I’m currently working with SLA escalation rules in Zoho Desk and ran into a limitation that I’m hoping someone here has solved more elegantly. As far as I can tell, SLA escalations only support fairly limited actions (like changing the ticket

• Zoho CRM Email Templates 100% Width No Background How?

  Hi, On the Zoho CRM Email Templates in setup > customization > templates > new templates > I choose blank template, but still it puts in a gray background and a max width for the email. I just want to make an email that looks like an email I would send from gmail that has no background or max width. How do you do this? 

• ZOHO CRM Quote Export / Quote Report

  How can I either Export my quote list, or create a Report that shows all quotes AND includes the NOTES field in a column. I attempted to Run a Report which includes ALL FIELDS, however it does not include the Notes Field (but oddly does include the fields

• Introducing Radio Buttons and Numeric Range Sliders in Zoho CRM

  Release update: 1. 2 March 2026: Currently out for CN, JP, AU and CA DCs (Free and standard editions). For other DCs, this will be released by mid-March. 2. 26 March 2026: CA, SA, AU, JP, CN DCs - Free, Standard, Professional, Enterprise, Ultimate, CRM

• Adding a Mark Up

  Can you use the discount column to be a mar up column on estimates and invoices?

• Subscription Statuses - Dunning

  How are other companies handling the scenario when customers don't pay and dunning takes over? Our issue is that in my situations, we want our customers to be able to catch up their late payments and continue their subscription after the dunning process

• Logo Doesnt appear on email

  Hi, 1. PROBLEM: mails sent to customer from zoho invoice ( Estimates and incoices etc.) Logo doesnt appaer on email. 2. SUGGESTION: there must be an option to select from google fonts if we want specific font to the pdf templates. thanks

• How to see Statement Details Shown in Unclassified Transactions in All Transactions?

  All, The list of Unclassified Transactions show the Statement Details and Descriptions. What is the method to see that column in the All Transactions list? -Thanks!

• Non-Avalara Tax Automation wtih Zoho Books

  We are paying a ridiculous amount for Avalara. Our team wants to make a change, but they're the only software fully integrated with Zoho. We also don't have the bandwidth to do this manually, so we do need some sort of automated software solution. We

• Migrating to the new outgoing webhook model in Zoho Connect

  Dear User, Outgoing webhooks configured across the Zoho Connect Integrations page, Zoho Flow, and Zapier will stop working after May 31, 2026. This is due to an upcoming upgrade to our outgoing webhook flow. This update is mandatory only for networks

• Create formula calculations in Assemblies for scaling quantities

  Something we have been encountering with our composite items is dealing with scaling of quantity of one or more items within the composite assembly relative to the number of complete units being sold. I.e. running the equation 2(n-1) on one of the assembly

• Lastest update

  The latest update to notepad has completely trashed all my notes. If I go to view it it just opens up a screen with a box with dotted lines around it for me to add something I can import saved nodes but you can't view them at all. Anybody else having

• Tip #67- Exploring technician console: Disable Input Devices- 'Insider Insights'

  Hello Zoho Assist Community! Picture this: you are in the middle of a critical remote session, carefully configuring a system or running an important update, and the customer accidentally clicks somewhere or types something that undoes your progress.

• What matters more in Zoho implementations: tools or system architecture?

  I recently worked on a full-stack migration for a catering equipment business using Zoho One with Shopify, and it raised a few interesting observations. The setup included migrating a large product catalog (around 9,700+ SKUs), integrating multiple supplier

• Facturation électronique 2026 - obligation dès le 1er septembre 2026

  Bonjour, Je me permets de réagir à divers posts publiés ici et là concernant le projet de E-Invoicing, dans le cadre de la facturation électronique prévue très prochainement. Dans le cadre du passage à la facturation électronique pour les entreprises,

• [Webinar] Solving business challenges: One tool for documents, forms, PDFs, e-signatures, and more

  Hi Zoho Writer users, Most businesses rely on multiple tools, such as a word processor, form builder, e-signature provider, and PDF editor, for their document workflows. Managing multiple subscriptions, switching between tools, and moving data across

• Deposit on invoice

  I'm trying to figure out how to customize an Estimate to include a Deposit/Retainer Invoice line within the Estimate. I tried creating my own custom field called "Deposit" where I manually inputted the deposit amount, which was nice. However, my employer

• Zoho NOTEBOOK: What are file size restrictions?

  I understand that Zoho NOTEBOOK is a free product, and what it offers is great. But I'm wondering what the file size restrictions are. When I record an audio note in Zoho Notebook, what is the maximum length of recording time/audio file size? When I wish to upload MP4 video, what is the maximum video size I can upload per Zoho Notebook restriction? Moreover, does Zoho Notebook use its own storage structure, or can I upgrade my storage for Zoho Notebook to add larger file attachments, videos and audio

• Concern Regarding Stock Validation in Inventory Management

  Hi Zoho Team, We would like to highlight a concern regarding stock validation in the inventory system. As per standard inventory management practices, if the stock level is zero, the system should not allow users to create a shipment, packing slip, or

• Automation Series #2: SLA vs Supervisor Rule in Zoho Desk

  SLA vs Supervisor Rule: Keeping tickets on track in Zoho Desk This post is part of the "Desk Automation Series," Chapter 1. Through this series, we will help you choose the right automation type in Zoho Desk by comparing commonly confused automations

• Zoho Recruit - Email Relay

  Good day, Has anyone succeeded in setting up an email relay for Office 365? If I add the details from https://support.microsoft.com/en-us/office/pop-imap-and-smtp-settings-8361e398-8af4-4e97-b147-6c6c4ac95353, I get the connection error. Regards, Eka

• Better use of contacts

  Zoho inventory has the ability to add multiple contacts to customers. However Zoho inventory doesn't currently provide a way to link a contact to objects like sales orders. This means that while you can tell what company has placed a sales order you can't

• Notebook AI limits

  Hi folks, Working with the AI transcription tools in Notebook, on the Mac App, which I find quite handy, but the one thing I am struggling with is the inability to either edit or copy the results of the transcript: I can't click in any of the boxes, and

• Disappointment with Zoho Payments

  Dear Gowdhaman, I am writing to inform you that I am removing Zoho Payments from my website. I cannot continue to disappoint my customers due to the lack of UPI support, as has been the case with my experience so far. Please note that the 0.5% transaction

• Zoho Commerce B2B

  Hello, I have signed up for a Zoho Commerce B2B product demo but it's not clear to me how the B2B experience would look for my customers, in a couple of ways. 1) Some of my customers are on terms and some pay upfront with credit card. How do I hide/show

• Rename system-defined labels in Zoho CRM

  Renaming system-defined labels is now available across all DCs. Hello everyone, Zoho CRM includes predefined system fields across modules to support essential CRM operations. Until now, the labels of these fields were fixed and could not be edited from

• Introducing parent-child ticketing in Zoho Desk [Early access]

  Hello Zoho Desk users! We have introduced the parent-child ticketing system to help customer service teams ensure efficient resolution of issues involving multiple, related tickets. You can now combine repetitive and interconnected tickets into parent-child

• Separate Items & Services

  Hi, please separate items and services into different categories. Thank you

• Log a call: Call Duration for Inbound is mandatory but inbound is optional

  Hi Team Can you advise on why the call duration for the inbound call type is a mandatory field? We have a use case where we are manually logging a call but do not use the call duration field. The field does not have the option to make it non mandatory

• Zoho Sign 2025–2026: What's new and what's next

  Hello! Every year at Zoho Sign, we work hard to make document signing and agreement execution easy for all users. This year we sat down with our head of product, Mr. Subramanian Thayumanasamy, to discuss what we delivered in 2025 and our goals for 2026.

• 【開催報告】東京 Zoho ユーザー交流会 NEXUS vol.1 ～ データドリブン経営・少人数組織のCRM活用・AIエージェントの最前線 ～

  ユーザーの皆さん、こんにちは。 コミュニティグループの中野です。 2026年3月27日（金）、東京・新橋にて「東京 Zoho ユーザー交流会 NEXUS vol.1」が開催されました。 今回は「マーケティング領域のZoho 活用法 × AI」をテーマに、ユーザーさん2名による事例セッション、Zoho 社員によるAIセッションなどを実施しました。 ご参加くださったユーザーの皆さま、ありがとうございました！ この投稿では、当日のセッションの様子や使用した資料を紹介しています。残念ながら当日お越しいただけなかった方も、ぜひチェックしてみてください。

• Monthly Webinar : Getting Started with Zoho LandingPage

  Our monthly Getting Started with Zoho LandingPage webinar is back! If you're building your first page and want a little guidance, this is where to start. Learn how landing pages fit into your strategy, generate leads, and improve conversions. Here’s what

• Mass emails - Allow preview of which emails will receive the email based on the criteria

  Feature request. Please allow us to view and confirm the exact recipients of the mass emails based on the criteria we've chosen before sending. It can be quite sensitive if you send the mass email to some wrong accounts accidently, so it would be great

• Limitation in Dynamic Constant Sum Based on Previous Question Selections in Zoho Survey

  Zoho Survey supports the Constant Sum question type, allowing respondents to distribute a fixed total (such as 100) across a set of options. However, it does not support dynamically populating these options based on selections made in a previous question.

• SAP Business One(B1) integration is now live in Zoho Flow

  We’re excited to share that SAP Business One (B1) is now available in Zoho Flow! This means you can now build workflows that connect SAP B1 with other apps and automate routine processes without relying on custom code. Note: SAP Business One integration

• Next Page