TransMail - Mail Agents

Mail Agent is used to group or categorize your Transactional emails at a high level. You can set up multiple domains under the same Mail Agent, to group the Transactional emails from those domains that fall under a particular category. This helps you to view all the transactions of the processed emails based on the Mail Agent. You can also configure webhooks, enable tracking (bounce, open and click), and upload files that can be added as inline images or attachments to your email. 

Configuring your domain with Mail Agents

Your transactional emails are sent using a Mail Agent. You can create multiple Mail Agents for different purposes. This will help you to group your transactional emails at a high level. Each Mail Agent should have at least one verified domain, to start sending emails. 

In case your primary domain is already in use and is sending/ receiving emails, you should set up a sub-domain or another secondary domain specifically for sending transactional emails. This will avoid the disruption of emails in your existing accounts. You should not use the domains added in your Mail Agent for any other purpose. The domain added in Mail Agent will be primarily used for return-path of the emails. Using a Mail Agent, you can send emails with the from-address containing the domain verified in that Mail Agent or a domain verified in another Mail Agent for the same TransMail account.


If you want to send you transactional emails using a domain verified in another Mail Agent, you need to enable that domain across all Mail Agents. Go to Sender Domains section to learn how to enable this setting. 

You can configure multiple Mail Agents for different sets of emails or for emails from different applications.

From the list of Mail Agents, select any Mail Agent to view the related details. The details related to the Mail Agent are grouped under different tabs:

  • Overview - A summary of the number of Transactions using the Mail Agent. 
  • Domains - Details of the domains that are linked with the particular Mail Agent.
  • Processed Emails - Logs of the emails that were processed using the Mail Agent.
  • Webhooks - To trigger HTTP call back to the application, based on configured events, in a Mail Agent. 
  • Email Tracking - To track the email activity - email open and click actions for the emails.  
  • File Cache - To upload any inline images, attachments that need to be sent in the email. 


You can get an Overview of the Mail Agent (for the last 15 days) in terms of the number of emails, the number of bounces, opened count, and so on. This can be based on different chunks of time periods, chosen by you. 

The number of emails sent vs count of emails opened/ clicked along with the count of hard/ soft bounces is plotted in a chart to provide you an easy overview at a glance. 


Every Mail Agent should be linked with at least a single domain. After adding a domain to a Mail Agent, you need to configure SPF, DKIM and MX records. In TransMail, It is mandatory to verify these records for sending transactional emails. Each Mail Agent can be associated with multiple domains. You can view the list of domains associated with the Mail Agent in this section. 

The Domain Verification page will provide you in-depth information about domains, along with detailed instructions to verify domains, edit a domain or delete a domain.  

Processed Emails

You can view the detailed log of all the emails processed by the Mail Agent in this section. The logs will be based on the processed time of the email. Select any email to view the status of the particular email. You can also use 'Search' to find the status of specific emails. 

The Processed Emails page has detailed instructions on using various parameters and also about the various delivery status associated with the email. 


In most simple terms, Webhooks are user-defined HTTP callbacks that are triggered by an event. In TransMail, Webhooks can be used to relay data based on recipient activity on the sent emails, to your application. This can be Opens/ Click or Bounces of the email. A Webhook instantly relays data to the configured URL and your application is instantly notified. 

The event which triggers the Webhook can be successful email open, click, or bounce notification. When the specific event occurs, the Webhook is triggered. That is, an HTTP POST request is made to the URL (or URI) configured by the developer to receive the webhook. The most useful feature of email webhooks is getting details on how the user responds via opens and clicks.

TransMail supports various types of Webhooks for different purposes. Refer here to learn about different types of Webhooks supported.

Email Tracking

When you send Transactional emails, tracking the email to understand user behavior becomes very vital for the application. Since Transactional emails are very critical, open, and click-tracking provides information on how the users respond to your emails.

In some cases, you might need to know whether the email delivered to your user was opened or not. Email Tracking helps you to track the click and open status of the emails sent via TransMail. 

This page provides you detailed information on Tracking and instructions to configure Tracking in TransMail.  

File Cache

When you send emails, you might need inline images or attachments that need to be sent with the email. Those attachments that are going to be used often, you can upload them in the File Cache. Each file (image or attachment) you upload to TransMail will have a unique FileCacheKey generated by the system. You need to use this FileCacheKey to link them to the Transactional emails sent by you. The total email size, including the attachments and inline images should not exceed 15 MB in size.  

Refer File Cache section for detailed instructions for uploading and including inline Images/ Attachments to the emails. 

Create a Mail Agent

You might have created a Mail Agent during the on-boarding process. To create and use additional Mail Agents, follow the instructions below:

  1. Log in to TransMail application
  2. Select 'Mail Agents' from the left panel
  3. In the Mail Agents section, the list of Mail Agents is displayed. 
  4. Click 'Add Agent' from the top bar to create a new Mail Agent.  
  5. Provide the Mail Agent nameDomain, and Description for the new Mail Agent.
  6. Click Add to create the new Mail Agent.

Connect your application to a Mail Agent

Transactional emails are generated by your application. You need to configure the application with the MailAgent in Transmail to trigger emails from the application. 

Follow the steps below to connect your application with TransMail service.

  1. Click on Mail Agents on the left panel of the dashboard. On the drop-down, select a Mail Agent which you want to connect with your application.
  2. On the top right corner of the Mail Agent, click on Setup Details (gear icon). A dialog with Setup Details will open.

  1. The Send Mail Token can be copied from here and can be used in your API or SMTP setup.

  1. Copy and use Send Mail Token to connect your application with this Mail Agent.

Delete a Mail Agent

You can remove the MailAgents that you no longer use or do not plan to use in the future. Only Postmaster has permission to delete a Mail Agent. 

Before deleting the Mail Agent, you have to initiate the Mail Agent shut down process. The data associated with your Mail Agent will be available for 45 days. You can delete this data anytime within 45 days. After 45 days, TransMail will automatically delete this information.

After shutdown initiation, the user will not be able to use the Mail Agent's verified domains for sending emails. However, the data associated with the Mail Agent will be still available. You will be able to view the processed emails section. After the shutdown is initiated:

  • You cannot revert it and send further emails. 
  • You will not be able to send any emails via HTTP or SMTP
  • All Mail Agent actions like scheduled emails, tracking, webhooks triggering etc will be blocked immediately.
  • After Shutdown, information such as processed email, logs, verified domains, and reports will remain till the deletion of the Mail Agent. 
  • After Mail Agent deletion, you can not send emails using the sender domain verified in that Mail Agent.
  • All the information associated with the Mail Agent will be deleted irreversibly.

Mail Agent Shutdown

To shut down a Mail Agent, follow the steps below

  1. Log in to TransMail application
  2. Launch Mail Agents section from the left panel. 
  3. Select the Mail Agent you want to delete.
  4. On top right corner click on the power icon to Shut down the Mail Agent.

  1. In the Shutdown Initiation popup, provide your password and click on Shutdown.

Points to remember

  • You can add and use up to 10 domains in your TransMail account.
  • All the domains you add can be associated to a single Mail Agent or multiple Mail Agents.
  • The domain should be verified, to use it in the Mail Agent for sending Transactional emails. 
  • You need to configure a bounce email address with the verified domain in the Mail Agent
  • You can use different domains, for sending different types of Transactional emails from the same MailAgent. This is purely based on your sending requirements. 
    • Example: The company Zylker sends two types of transactional emails - Daily reports and account alerts from the same Mail Agent. It uses the sub-domain for daily reports and for account alerts. Both these verified sub-domains are part of the same Mail Agent.
  • However, you can also send different emails using different Mail Agents. For instance, Zylker can use Mail Agent 1 to send welcome emails and Mail Agent 2 to send daily reports. Mail Agent 1 will have the sub-domain added to it. Mail Agent 2 will have sub-domain added to it.
  • If you delete a shared sender domain you can not send emails using this domain in any Mail Agents.
  • The maximum number of recipients you can add in your email (which includes to, cc and bcc fields) is 70.
  • The maximum size of the email you can send including the headers, in-line images, and attachments is 15MB.
  • TransMail does not support certain formats of in-line images and attachments. Click here to view the list of unsupported formats.


Before you get started it is important to know that TransMail is for sending transactional emails like welcome emailers, password resets emails, OTPs. We do not support sending of bulk emails or promotional emails like newsletters or marketing campaign emails. If you are looking for a bulk email provider, check out Zoho Campaigns.