Transactional email and email API setup
Password resets, order confirmations, booking reminders and alerts are emails customers are waiting for. If they’re slow, missing or in spam, customers can’t sign in, pay or show up.
The short answer
Transactional emails are automatic messages triggered by what a customer does. We set them up through a dedicated sending service and its email API or SMTP: templates, authentication (SPF, DKIM, DMARC), a separate sending subdomain, bounce handling, and delivery logs, integrated with your website or application.
What’s included
- Choosing a transactional email service to fit your volume.
- API or SMTP integration with your website, app or system.
- A separate sending subdomain, so marketing can’t affect these messages’ reputation.
- Authentication: SPF, DKIM and DMARC, aligned.
- Templates for each notification, readable on phones.
- Bounce and complaint handling, delivery logs and alerts.
How we do it
- List every automatic email your system sends.
- Set up the sending service and DNS.
- Integrate through the API or SMTP.
- Build the templates.
- Test each message and monitor the first weeks.
Transactional versus marketing email
Mailbox providers treat them differently. Gmail excludes transactional messages, such as password resets, reservation confirmations and form submission confirmations, from its one-click unsubscribe requirement [1]. Keeping them on a separate sending stream from newsletters protects their delivery.
Email notification systems
For businesses that need a notification system (alerts to staff, reminders to customers, reports on a schedule), we design the triggers, templates and sending, and connect them to your existing software.
Common questions
Which email API should we use?
It depends on volume, budget and where your customers are; we recommend one after a short look at your needs.
Can transactional emails go through our normal mailbox?
Not reliably: mailbox services limit automated sending, and mixing them with staff email risks both.
Do transactional emails need an unsubscribe link?
Not for true transactional messages. Gmail’s one-click unsubscribe requirement applies to marketing, not to password resets or confirmations [1].
Sources
Numbers in this guide come from these studies and publications. Links open the original.
- Email sender guidelines FAQGoogle Workspace Admin Help (Gmail)Requirements for senders of 5,000+ messages a day to Gmail since February 2024; stricter enforcement, including rejections, since November 2025.