How To: Integration with a 3rd Party SMTP email provider

3rd Party SMTP providers

There are many 3rd Party SMTP email providers available on the market today that specialise in sending large quantities of emails in bulk (and doing their best to avoid spam filters).

Here is a list of 6 providers you may like to look into. In your internet search engine, use the search term "Transactional Email Service" to find more:

  • SendGrid
  • Amazon SES (Simple Email Service)
  • Mailgun
  • Mailjet
  • Postmark
  • SendinBlue


Why use a 3rd party SMTP service?

For >99% of our customers, we recommend using your own SMTP server that your IT team manages for you. In nearly every case, we DO NOT recommend using a 3rd party SMTP service. This is because every email service provider (such as gmail) tracks the reputation of all domains individually and it is very important that you are who you say you are when sending emails.

However, there are some situations where using another SMTP server may be useful to you:

  1. Maximise Delivery: using a service that specialises in sending large amounts of emails in quick bursts will have automatic features built in to manage feedback from email service providers (ESP's). This means you don't need to use the delay mechanism in VETtrak that could tie up your screen while it slowly sends each email.
  2. Email tracking and analytics: most 3rd party providers will supply you with a dashboard to track email bounces and opens
  3. Infrastructure/Security: You don't have access to an SMTP server. This could be due to extra security considerations that your organisation imposes.

Once you have decided to try a 3rd Party SMTP email provider, check the pricing and sign up for an account. You will then need to authenticate the "Sending" domain before you can use the SMTP server.


How to Authenticate the "Sending" domain?

Your 3rd party SMTP provider will give you instructions on how to authenticate the sending domain. This normally involves creating some DNS records for the domain that the SMTP provider will verify. You should always use a subdomain or a brand new domain for sending your emails through the 3rd party SMTP server. Mixing a 3rd party SMTP server with your existing one is much harder to setup and will likely damage your ESP reputation.

Option #1: Subdomain

A subdomain is a great option if you are wanting to increase the deliverability of your emails. You will need to request this through your IT team and is normally free of charge. For example, if your domain is a subdomain for sending your VETtrak emails could be Remember to use a "Reply To" address that your recipients can use to send replies to a monitored inbox.

Option #2: New Domain

A new domain for sending emails may be required for organisations that have strict security requirements around the management/changes to their domain. You may also like to do this for testing/learning purposes.

Example -

As an example, the free domain registration service may be used to register the domain as a fictional RTO domain. You should probably use a paid service such as Go Daddy, NetRegistry or Crazy Domains to register your own new domain (if you are not using a subdomain).

Within the SendGrid account, go to Settings -> Sender Authentication ->Authenticate Your Domain to start the verification process. 3 CNAME records are generated that need to create in my DNS manager. 



If you are using freenom, go to My Domains -> Domain Management and add the records you are shown:



Go back to the SendGrid session, and click Verify to check that the DNS records are publicly available and complete the authentication process.



How to add the SMTP server to VETtrak?

Your 3rd party SMTP provider will give you information on how to connect to it's SMTP server. For SendGrid, you will need to create an API key. Navigate to Settings -> API Keys -> Create API Key. You can name this key anything you like.

In VETtrak, add the SMTP server address (e.g.., the port (e.g.. 587), the SSL/TLS connection method, authentication type, username (for SendGrid this should always be 'apikey'), and the password (for SendGrid, this is the API password you were given when creating the API key)



Known Limitations/Other Considerations

  • Be aware of how replies are handled. Some 3rd party SMTP providers will give you functionality to redirect replies automatically for you. For example, Mailgun has "routing" functionality that will let you set up rules that will forward you any matching emails. SendGrid has inbound parsing functionality which will do something similar using webhooks.
  • Check the pricing carefully. Most providers will have a free tier (e.g.. Mailgun gives you 10,000 free emails per month). If you want to control your spending, look for a provider that gives you a setting to limit the number of emails you can send per month.
  • VETtrak can only be configured to use 1 SMTP server. It's not possible to use both your existing SMTP server and a 3rd party SMTP server at the same time for sending emails
  • Test your SMTP setup carefully. Send test emails to a variety of email addresses (e.g.. Gmail, Outlook etc) and check with the recipients that they have received the emails and if there any were detected as spam or were delayed. The analytic tools provided by your SMTP server should help trace the status of email delivery. If you need assistance, please reach out to the SMTP server support team with your issue.
  • VETtrak does not have a relationship with any SMTP provider. Please check directly with the provider about their terms and conditions of service.

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