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Custom email domain

Send certificates from your own email address

Certificate emails arrive from certificates@yourdomain.com with your organization's name, sent through your own email server or Resend account. Available on Plus and Professional.

Start with Plus Read the setup guide

What recipients see

An email from you, not from a vendor

The same certificate email, with your name and address on it.

Starter and Free
From
Acme Training via CertSeal <cert_delivery@certseal.app>
Reply-To
your account owner
Plus and Professional
From
Acme Training <certificates@yourdomain.com>
Reply-To
training@yourdomain.com

Your Fire Safety certificate

Hi Ann, congratulations on completing Fire Safety. Your certificate is ready.

View your certificate →

Sent by Acme Training using CertSeal. Not expecting this email? Report it.

Two ways to connect

Use the email service you already trust

Your emails go through your own server or account, under your own sending reputation.

Your SMTP server

Connect the mailbox or email service you already use: Microsoft 365, Google Workspace, Amazon SES, SendGrid, Postmark, Mailgun or your own server. CertSeal connects over TLS on port 587, 465 or 2525.

  • Host, port, username and password
  • A From address your server may send as
  • Sent and failed status for every recipient

Your Resend account

Paste an API key from your own Resend account and send from any domain you've verified there. Add a webhook in Resend and delivered, bounced and spam results show up on your batches.

  • A Resend API key with sending access
  • A From address on your verified domain
  • Optional delivery tracking through a webhook

Capabilities

Your address, with CertSeal's safety net

Your name, your address

Recipients see “Acme Training” <certificates@yourdomain.com> instead of “Acme Training via CertSeal”. The email is authenticated with your own domain's SPF and DKIM, set up with your email provider.

Replies go where you want

Set a Reply-To such as training@yourdomain.com, so questions from recipients reach the right team instead of the account owner's inbox.

Tested before it's used

Save and send test email sends a message through your server to you first. CertSeal only switches over once that test arrives.

Paced to your provider's limits

Choose how many emails per minute your server or account should send. A large batch is spread out instead of hitting your provider's rate limit.

A safe fallback

If your server stops accepting the login or your key is revoked, certificate emails go out from CertSeal's address so they still arrive, and your owners and admins get an email saying why.

Credentials kept encrypted

Your SMTP password and Resend key are encrypted when they're saved and never shown again. Leave the field blank to keep the saved one when you edit other settings.

Set it up

Four steps, about five minutes

  1. 01

    Open Email sending

    Owners and admins open Organization in the sidebar and scroll to Email sending.

  2. 02

    Pick SMTP or Resend

    Enter your server's details or your Resend API key, the From address, and how many emails per minute to send.

  3. 03

    Send the test email

    Click Save and send test email. When it reaches your inbox, every certificate email switches to your address.

  4. 04

    Send batches as usual

    Nothing else changes. Batches, Zoom automations, Zapier, the REST API and AI apps all send from your address.

Questions about custom email domains

What teams ask before switching

Which plans include a custom email domain?
Plus and Professional, and Custom plans. On Free and Starter, certificate emails come from CertSeal's address as "Your organization via CertSeal". See pricing.
Do I need to change my DNS for CertSeal?
No. Your email provider does the sending, so set up SPF, DKIM and DMARC with them, as you would for any email you send from your domain. CertSeal only needs the server login or API key.
Do certificate pages move to my domain too?
No. This changes who the email comes from. The link in the email still opens the recipient's certificate page on CertSeal, where it can be verified.
Will I still see which emails were delivered?
With your Resend account and its webhook, yes: delivered, bounced and marked-as-spam results show on the batch. An SMTP server doesn't report back, so recipients show Sent or Failed.
What happens if my email server stops working?
CertSeal stops using it and sends from its own address instead, so certificates still arrive. Your owners and admins get an email with the reason, and saving working settings switches back.
Does the email still mention CertSeal?
Yes, in a short footer: "Sent by your organization using CertSeal" and how to report an unexpected email. It helps recipients trust the email and can't be removed.
Can I use Microsoft 365 or Gmail?
Yes. Microsoft 365 needs SMTP AUTH turned on for the mailbox and allows about 30 emails a minute. Gmail and Google Workspace need an app password. The setup guide lists the settings for each provider.

Send certificates from your own address

Available on Plus and Professional. Set it up in a few minutes from your Organization page.

Start with Plus See pricing