Email Delivery

Email Delivery controls how WebinarStack sends automation emails for your account. When you connect an email provider, webinar automation emails can come from your own verified sending domain instead of the WebinarStack platform default.

Use this guide to understand what Email Delivery is, how SendGrid and Postmark fit into the system, what each setup field means, how automation emails are sent, and how to prepare for future sending-provider options.

The Short Version

Email Delivery is the account-level sending provider for WebinarStack automation emails.

Concept	What It Means
Supported providers	SendGrid and Postmark.
Active provider model	One connected email provider per account at a time.
Main use	Sending automation email actions to webinar attendees.
Fallback behavior	If no provider is connected, automation emails use the WebinarStack platform default.
Sender address	The saved account From email is used unless a specific automation rule overrides it.
Verification	WebinarStack sends a real test email before saving credentials, then checks provider domain verification status.
Provider switching	Saving SendGrid replaces Postmark for the account, and saving Postmark replaces SendGrid.

The most important practical rule is this: connect Email Delivery before you rely on registration confirmations, reminders, follow-ups, or any other attendee-facing automation email.

Email Delivery Versus Other Integrations

WebinarStack has several integration surfaces. They are related, but they do different jobs.

System	Direction	What It Does	Example
Email Delivery	WebinarStack sends email through your provider.	Sends automation emails through SendGrid or Postmark.	Send a registration confirmation from `events@yourdomain.com`.
Integration actions	WebinarStack updates another marketing tool.	Adds or updates contacts, tags, list membership, groups, or fields in tools such as Mailchimp, Kit, ActiveCampaign, or MailerLite.	Tag attendees who watched 75 percent of the webinar.
Webhook actions	WebinarStack sends JSON to your URL.	Calls your backend, CRM workflow, or no-code automation.	POST high-intent attendee data to a custom lead router.
SMS actions	WebinarStack sends text messages through Twilio SMS.	Sends attendee reminders or follow-ups through SMS delivery.	Send a one-hour reminder to opted-in attendees.

Email Delivery is not the same as a marketing integration. Connecting SendGrid or Postmark gives WebinarStack a way to send email. It does not automatically add contacts to a SendGrid list, subscribe someone to a Postmark broadcast list, tag contacts in a CRM, or replace webhook workflows.

You can combine these systems. For example, a Registered automation can send a confirmation email through SendGrid, add the contact to Kit, ActiveCampaign, Mailchimp, or MailerLite through an integration action, and call your CRM through a webhook.

Where To Manage Email Delivery

Manage the account sending provider from the dashboard:

Open Settings.
Select the Email tab.
Use the Email Delivery card to connect, update, or disconnect a provider.

You can also check the current provider from a webinar:

Open a webinar.
Go to the Settings tab.
Find the Email Delivery status card.

The webinar-level card is a status shortcut. The actual provider connection is account-wide, so changing it affects automation emails across the account.

The Mental Model

Email Delivery has four layers.

Layer	What Happens
Account provider	Your account can connect one email provider, currently SendGrid or Postmark.
Provider credential	WebinarStack stores the provider credential securely and never shows the key back in the UI.
Sending domain	WebinarStack derives the sending domain from the From email, such as `yourdomain.com` from `events@yourdomain.com`.
Automation email action	When an automation email sends, WebinarStack looks for the connected account provider and routes the email through it.

The flow looks like this:

You connect SendGrid or Postmark in Settings.
WebinarStack sends a test email with the credential and From email you entered.
If the test send succeeds, WebinarStack saves the credential for the account.
WebinarStack checks whether the sending domain is verified with the provider.
When an automation email fires, WebinarStack uses the connected provider.
If no provider is connected, WebinarStack uses the platform default sender.

The test send and the domain verification check are related but not identical. A provider can accept a test send while DNS verification is still pending. In that case, email can work, but deliverability may be weaker until the domain is verified.

Supported Providers

SendGrid

Choose SendGrid when your team already uses SendGrid for transactional email or wants to manage sending identity, suppression lists, bounce handling, and provider analytics there.

In WebinarStack, SendGrid uses:

Item	Meaning
Provider option	`SendGrid`
Credential field	API key
Sending endpoint	SendGrid Mail Send API
Sender requirement	The From email should belong to a verified SendGrid sender or authenticated domain.
Domain verification check	WebinarStack checks SendGrid domain authentication status for the sending domain.

Before connecting SendGrid, prepare:

A SendGrid API key that can send mail.
A verified sender identity or authenticated domain in SendGrid.
Access to your DNS records if domain authentication is not finished yet.
The From email you want attendees to see.

If you use a restricted SendGrid API key, make sure it can send email. If the key cannot read domain authentication status, WebinarStack may still send test email but show the domain as unverified.

SendGrid domain authentication reference: How to set up domain authentication.

Postmark

Choose Postmark when your team already uses Postmark for transactional email, especially if you prefer Postmark’s server-based model and sender-signature workflow.

In WebinarStack, Postmark uses:

Item	Meaning
Provider option	`Postmark`
Credential field	Server token
Sending endpoint	Postmark Email API
Message stream	Outbound
Sender requirement	The From email should be a verified sender signature or belong to a verified sending domain in Postmark.
Domain verification check	WebinarStack checks Postmark sender signature DKIM verification for the sending domain.

Before connecting Postmark, prepare:

A Postmark server token for the server that should send WebinarStack mail.
A verified sender signature or domain in Postmark.
Access to your DNS records if DKIM is not finished yet.
The From email you want attendees to see.

Postmark setup reference: Getting started with Postmark.

Choosing A Provider

Both providers can work well. The best choice is usually the provider your team already trusts for transactional email.

Choose This	When
SendGrid	Your team already uses SendGrid, wants broad email infrastructure controls, or has an authenticated SendGrid sending domain ready.
Postmark	Your team already uses Postmark, prefers server tokens and sender signatures, or wants webinar mail grouped with other transactional Postmark traffic.
Platform default	You are testing, have not prepared DNS yet, or do not need a branded sending provider immediately.

For production launches, use a verified sender on a domain you own. Avoid sending from free mailbox domains such as Gmail, Outlook, Yahoo, or iCloud. Those domains are not controlled by you and usually cannot be authenticated for a third-party sending provider.

Setup Walkthrough

1. Pick The Sending Address

Choose the address attendees should see in their inbox.

Good examples:

events@yourdomain.com
webinars@yourdomain.com
training@yourdomain.com
support@yourdomain.com

Avoid using a personal address if webinar email should be owned by the business. A shared sender is easier to authenticate, easier to monitor, and easier to keep stable when team members change.

The part after @ becomes the sending domain that WebinarStack checks. For events@yourdomain.com, the sending domain is yourdomain.com.

2. Verify The Sender In Your Provider

In SendGrid, verify a sender identity or authenticate the sending domain.

In Postmark, verify a sender signature or sending domain.

Domain authentication is strongly recommended because it gives email providers DNS proof that your provider is allowed to send mail for your domain. That usually involves records such as SPF, DKIM, and provider-specific CNAME or TXT records.

DNS changes can take time to propagate. If you just added records, WebinarStack may show the domain as unverified until the provider detects the records.

3. Create The Provider Credential

Create the credential in the provider you chose:

Provider	Credential
SendGrid	API key
Postmark	Server token

Treat this credential like a password. Do not paste it into support tickets, docs, screenshots, or AI tools. Enter it only in WebinarStack and in systems that are supposed to send through the provider.

4. Open Email Delivery Settings

In WebinarStack:

Open Settings.
Select Email.
Find Email Delivery.
Select SendGrid or Postmark.

5. Complete The Fields

The form shows fields based on the selected provider.

Field	Meaning	How To Use It
Email provider	The sending provider WebinarStack should use for automation emails.	Choose SendGrid or Postmark. Only one can be active at a time.
API key	SendGrid credential used to send email.	Paste a SendGrid API key that can send mail. This field appears for SendGrid.
Server token	Postmark credential used to send email.	Paste the Postmark server token for the server that should send WebinarStack emails. This field appears for Postmark.
From email	The sender address used by default for automation emails.	Enter a verified sender address such as `events@yourdomain.com`.

The From email must be valid and should be verified in the selected provider account. If it is not verified, the test send may fail or later sends may be rejected by the provider.

6. Save And Verify

Click Save & Verify.

WebinarStack immediately sends a test email:

From: the From email you entered.
To: your logged-in user email.
Subject: WebinarStack email delivery test.
Body: a short confirmation that delivery is working.

If the test send fails, WebinarStack does not save the credential. Fix the provider key, token, sender, or provider-side configuration, then try again.

If the test send succeeds, WebinarStack saves the provider and clears the secret field from the form. The key is not displayed again.

7. Check Domain Verification

After the provider is saved, WebinarStack checks the sending domain.

If the provider reports the domain as verified, no warning appears.

If the provider reports the domain as unverified, WebinarStack shows a warning with:

A message that the sending domain is not verified.
A Check Again button.
A link to the provider’s DNS setup documentation.

Use Check Again after you update DNS records in SendGrid or Postmark. DNS propagation can take minutes or hours, and in some cases up to 48 hours.

8. Send A Real Automation Test

After Email Delivery is connected, test at least one real automation email:

Open a webinar.
Go to Automations.
Create or edit an email automation.
Use the test email tool in the email preview.
Send the test to an inbox you can inspect.
Confirm the sender, subject, content, links, unsubscribe link, and any calendar invite attachment.

The automation test email uses the connected account provider when one is configured. This is the best way to confirm the actual webinar email path.

Updating Or Switching Providers

Use Change when you need to update the provider, key, token, or From email.

When you save a different provider, WebinarStack replaces the current provider for the account. You do not need to edit individual automation rules. Existing automation email actions will use the newly connected provider the next time they send.

Examples:

If SendGrid is connected and you save Postmark, future automation emails use Postmark.
If Postmark is connected and you save SendGrid, future automation emails use SendGrid.
If you update the From email, future automation emails use the new account sender unless an individual rule overrides it.

Use Disconnect Provider when you want to remove the account provider. After disconnecting, automation emails fall back to the WebinarStack platform default. Existing automation rules remain in place.

What Uses Email Delivery

Email Delivery applies to attendee-facing automation email sends.

Message Or Feature	Uses Connected Provider?	Notes
Automation email action	Yes	The main production send path for webinar email automations.
Automation test email	Yes	Uses the connected provider when present, otherwise falls back to platform default.
Email Delivery setup test	Yes	Uses the key or token you are trying to save. The credential is saved only after this test succeeds.
Calendar invite attachment on automation email	Yes	The attachment is sent through the same provider as the automation email.
Account invitation emails	No	These use the WebinarStack platform sender.
Billing and usage warning emails	No	These use the WebinarStack platform sender.
Chat forwarding emails to hosts	No	These use the WebinarStack platform sender.
Integration actions	No	Integration actions update external tools; they do not send email through Email Delivery.
Webhook actions	No	Webhooks send HTTP requests, not email.
SMS actions	No	SMS uses the SMS delivery system.

When in doubt, ask: “Is this an automation email action to an attendee?” If yes, Email Delivery is the sending provider. If not, it may be a different WebinarStack system.

How Automation Email Sends Work

When an automation email fires, WebinarStack does more than simply pass text to SendGrid or Postmark.

The automation trigger fires, such as registered, joined, no-show, watched percentage, offer click, poll response, chat message, before session, or after session.
WebinarStack loads the automation rule, attendee registration, and webinar.
WebinarStack checks whether the attendee has opted out of email.
If the rule has a delay, WebinarStack applies the delay when appropriate.
WebinarStack resolves the attendee’s webinar URL, replay URL, session date, session time, and timezone context.
WebinarStack renders the rich-text email body into branded email HTML.
WebinarStack creates a plain-text version.
WebinarStack resolves personalization tokens.
WebinarStack adds the unsubscribe link.
If the rule has Attach calendar invite (.ics) enabled, WebinarStack builds the calendar attachment.
WebinarStack looks up the connected account email provider.
WebinarStack chooses the sender address.
WebinarStack sends the message through SendGrid, Postmark, or the platform default.
WebinarStack marks the automation execution as completed or failed.

Automation email delivery is asynchronous. Attendees do not wait in the browser for your email provider to finish.

Sender Address Rules

Automation emails choose the sender in this order:

Priority	Sender
1	Rule-level From name plus rule-level From email, when both are set on the email action.
2	Account-level From email from Email Delivery.
3	WebinarStack platform default sender.

This gives you a default account sender while still allowing special-case automation rules to use another sender.

Use rule-level sender overrides carefully. The provider must allow the sender you choose. For example, if your account Email Delivery provider is SendGrid and an automation rule uses ceo@yourdomain.com, SendGrid still needs to accept that sender. If the rule-level From email is not verified or not allowed, the provider may reject the send.

For most accounts, the cleanest setup is:

Use one verified account From email in Email Delivery.
Leave rule-level From email blank unless a specific campaign needs a different sender.
Use From name for recognizable branding, such as Acme Webinars or Jamie from Acme.

Personalization Tokens

Automation emails can include WebinarStack tokens in the subject and body. These are resolved when the email sends.

Common tokens include:

Token	Meaning
`{{attendee_name}}`	The attendee’s name.
`{{attendee_email}}`	The attendee’s email address.
`{{webinar_title}}`	The public webinar title.
`{{session_date}}`	The attendee’s localized session date.
`{{session_time}}`	The attendee’s localized session time.
`{{session_timezone}}`	The attendee’s session timezone abbreviation.
`{{host_name}}`	The webinar host display name.
`{{watch_link}}`	The attendee’s watch link.
`{{replay_link}}`	The attendee’s replay link.
`{{unsubscribe_link}}`	The attendee’s unsubscribe link.
`{{chat_message}}`	The chat message that triggered a chat automation.

Test emails use sample token values so you can inspect formatting before launch.

Unsubscribe And Opt-Out Behavior

Automation emails include unsubscribe handling.

When an attendee opts out:

WebinarStack stores the opt-out state on the registration.
Future automation email sends for that registration are skipped.
The automation execution is marked as skipped because of opt-out.

Opt-out handling is checked before any delayed email send. This matters when an email is scheduled for later: if someone opts out after registering but before the delayed email sends, the delayed email is skipped.

Calendar Invite Attachments

Email automation rules can attach a calendar invite file.

Use Attach calendar invite (.ics) for emails such as:

Registration confirmations.
24-hour reminders.
1-hour reminders.
Session reschedule notices.

The calendar invite is built at send time from the attendee’s actual session time. That means it can reflect:

The webinar title.
The attendee’s registration token.
The attendee’s effective session start time.
The webinar timezone behavior.
The attendee-facing watch URL.

The same Email Delivery provider sends the email and the calendar attachment.

WebinarStack also checks message size before sending. If the rendered email plus attachment is too large, the send is rejected before hitting the provider instead of being retried repeatedly.

Domain Verification

Domain verification is about deliverability and trust.

When WebinarStack checks verification, it asks the connected provider whether the sending domain appears verified:

Provider	What WebinarStack Checks
SendGrid	Domain authentication status for the sending domain, including DKIM status when available.
Postmark	Sender signature or domain DKIM verification status for the sending domain.

If the domain is not verified, email may still send, but inbox placement can be worse. Recipients may see warnings, messages may land in spam, and mailbox providers may be less willing to trust your mail.

Good deliverability habits:

Send from a domain you own.
Complete provider DNS setup before launch.
Use a consistent From email for webinar mail.
Keep subject lines clear and honest.
Avoid link shorteners in attendee emails.
Test Gmail, Outlook, Apple Mail, and any inboxes common in your audience.
Monitor bounces, spam complaints, and suppression lists in your provider.
Warm up new sending domains gradually if you expect high volume.

Provider-Specific Sending Behavior

You do not need to configure these details in the UI, but they explain why one provider may behave differently from another.

Behavior	SendGrid	Postmark
Authentication	Bearer API key.	Postmark server token.
Email API	Mail Send API.	Email API.
Sender field	WebinarStack separates sender name and email when the sender is formatted as `Name <email@domain.com>`.	WebinarStack passes the sender string as the Postmark `From` value.
Reply-To	Supported when the automation or system call provides one.	Supported when the automation or system call provides one.
Calendar attachments	Sent through SendGrid attachments with calendar-specific handling.	Sent through Postmark attachments with calendar content type preserved.
Provider errors	Failed provider responses surface as SendGrid API errors.	Failed provider responses surface as Postmark API errors.

These provider differences are handled by WebinarStack. Your automation rule should not need provider-specific formatting.

Common Setup Patterns

Branded Webinar Sender

Use this when you want all attendee automation email to come from one brand address.

Create webinars@yourdomain.com.
Verify yourdomain.com in SendGrid or Postmark.
Connect the provider in WebinarStack.
Use webinars@yourdomain.com as the account From email.
Leave automation rule-level From email fields blank.

Different Sender For A Special Campaign

Use this when most emails should use the account sender, but one webinar campaign needs another sender.

Keep the account From email connected in Email Delivery.
Verify the special sender in the provider.
Open the automation email rule.
Set both From name and From email on that rule.
Send a test email from the automation editor.

If the provider rejects the rule-level sender, switch back to the account sender or verify the rule-level sender with the provider.

Send Email And Update A Marketing List

Use this when you want WebinarStack to send the attendee email and also sync the attendee to a marketing tool.

Connect SendGrid or Postmark in Email Delivery.
Connect the marketing tool in Settings > Integrations.
Create an email automation for the attendee-facing message.
Create an integration automation for the list or tag update.
Use conditions so each action only runs for the right attendees.

Email Delivery sends the email. The marketing integration updates the external marketing system.

Switch Providers Before Launch

Use this when you tested with one provider but want to launch with another.

Connect the new provider in Email Delivery.
Wait for the setup test email to succeed.
Check domain verification.
Send a test email from at least one automation.
Confirm the inbox sender and links.
Launch.

Existing automation rules do not need to be recreated.

Troubleshooting

The Save Button Is Disabled

Check that:

A provider is selected.
The API key or server token field is not blank.
The From email is a valid email address.

Test Send Failed

The credential is not saved when the setup test fails.

Check:

The API key or server token was copied correctly.
The credential belongs to the provider you selected.
The credential has permission to send email.
The From email is verified or allowed in the provider.
The provider account is active and not suspended.
The provider has not blocked sending because of billing, compliance, or suppression settings.

If the error mentions SendGrid, fix the SendGrid key or sender. If it mentions Postmark, fix the Postmark token or sender.

Domain Shows As Unverified

The saved provider can send a test email, but the sending domain is not verified according to the provider.

Check:

The From email domain is the domain you intended to verify.
DNS records were added to the correct DNS zone.
DNS records were copied exactly from SendGrid or Postmark.
CNAME, TXT, SPF, and DKIM records are not duplicated incorrectly.
The provider itself shows the domain or sender as verified.
Enough time has passed for DNS propagation.

After fixing DNS, click Check Again in WebinarStack.

Emails Send From The Wrong Address

Check the sender priority:

The automation rule may have a rule-level From name and From email.
If not, WebinarStack uses the account From email from Email Delivery.
If no provider is connected, WebinarStack uses the platform default.

Open the automation rule and inspect the email action fields. If you want the account-level sender, clear the rule-level From email.

Some Emails Use My Provider And Others Do Not

Email Delivery is for automation email actions. Other system emails may use the WebinarStack platform sender.

Common examples that do not use your connected provider:

Account invitation emails.
Billing or usage warning emails.
Host chat-forwarding notifications.

This separation keeps attendee-facing automation delivery configurable while platform and account-management mail remains controlled by WebinarStack.

Automation Email Did Not Send To An Attendee

Check:

The automation rule is enabled.
The trigger actually fired for that attendee.
Rule conditions passed.
The attendee has not opted out of email.
The delay or session timing has elapsed.
The provider accepted the send.
The message was not suppressed, bounced, or rejected inside SendGrid or Postmark.

For webhook and SMS actions, WebinarStack has channel-specific delivery history. Email provider-level delivery details live primarily in SendGrid or Postmark.

Calendar Invite Is Missing

Check:

The automation action is an email action.
Attach calendar invite (.ics) is enabled.
The attendee has a valid session time.
The email was not blocked by opt-out or provider rejection.
The message did not exceed the size guard.

Inbox clients render calendar attachments differently. Test the same email in the inboxes your audience uses most.

Provider Shows Bounces Or Suppressions

WebinarStack sends the email request to your provider. The provider then handles final delivery, bounces, suppressions, spam complaints, and mailbox-provider responses.

Open SendGrid or Postmark to inspect:

Bounces.
Blocks.
Suppressions.
Spam complaints.
Provider delivery events.
Account compliance warnings.

If a recipient is suppressed in the provider, WebinarStack may successfully submit the email while the provider refuses final delivery.

Security And Privacy

Email provider credentials are sensitive.

WebinarStack’s Email Delivery system is designed around these safeguards:

Safeguard	Meaning
Test before save	Credentials are only saved after a successful test send.
Encrypted storage	Provider keys and tokens are stored encrypted.
Secret not returned	The saved key or token is not displayed back in the UI.
Account scoping	Provider credentials belong to the current account.
One active provider	The account has one active email sending provider at a time.
Provider isolation	Tenant sends use the tenant credential directly instead of mutating a shared provider client.

Operational best practices:

Rotate provider credentials if someone leaves the team.
Use the least privileged key that can still send email and support verification checks.
Do not paste provider keys into AI tools, chat systems, spreadsheets, or screenshots.
Store DNS records and provider setup notes in your internal documentation.
Use provider logs to monitor unusual sending behavior.

Working With Future Providers

WebinarStack is structured so more email providers can be added over time.

The user-facing model should remain the same:

Choose a provider.
Enter the provider credential.
Enter a verified From email.
Send a setup test.
Save the credential only after the test succeeds.
Check domain or sender verification.
Route automation email actions through the connected account provider.

As new providers are added, they should appear in the same Email Delivery area instead of creating separate setup flows. Provider-specific fields may differ, but the account-level model should stay consistent.

When evaluating a future provider, ask:

Does it support transactional email sending?
Does it support verified domains or sender identities?
Does it expose clear API errors when a send fails?
Does it support HTML and plain-text bodies?
Does it support reply-to addresses?
Does it support calendar or file attachments if needed?
Does it provide delivery logs, bounce handling, and suppression management?
Does it fit the one-provider-per-account model?

Helpful AI Prompts

You can ask an AI assistant for help planning email setup, DNS review, or troubleshooting. Do not paste API keys, server tokens, private DNS account access, or attendee data into an AI tool.

Choose A Sending Address

I am setting up transactional webinar email for my company.
Our domain is [yourdomain.com].
Recommend 3 sender addresses for webinar confirmations, reminders, and follow-ups.
Explain the tradeoffs between using a shared sender like webinars@yourdomain.com and a personal sender like jamie@yourdomain.com.
Do not ask for or include any API keys.

Prepare A DNS Checklist

I am connecting [SendGrid/Postmark] to send webinar automation emails from [events@yourdomain.com].
Create a DNS setup checklist I can give to my domain administrator.
Include SPF, DKIM, CNAME/TXT record review, propagation expectations, and how to verify the provider sees the domain as authenticated.
Do not include or request API keys.

Troubleshoot An Unverified Domain

WebinarStack says my sending domain is unverified after I connected [SendGrid/Postmark].
My From email is [events@yourdomain.com].
Give me a step-by-step troubleshooting process that checks provider sender verification, DNS zone selection, record names, record values, duplicate SPF records, DKIM status, and DNS propagation.
Do not ask for secrets or private account access.

Audit A Launch Email Setup

Review this webinar email launch checklist and improve it:
- Provider: [SendGrid/Postmark]
- From email: [events@yourdomain.com]
- Automation emails: confirmation, 24-hour reminder, 1-hour reminder, attended follow-up, no-show follow-up
- Calendar invite attachment: [enabled/disabled]
- Test inboxes: Gmail, Outlook, Apple Mail

Add deliverability, unsubscribe, sender identity, and provider-log checks.
Do not ask for API keys or attendee data.

Launch Checklist

Before relying on automation email for a webinar launch:

Choose SendGrid or Postmark.
Verify the sender or sending domain in the provider.
Connect the provider in Settings > Email.
Confirm the setup test email arrives.
Resolve any domain verification warning.
Send an automation test email.
Check the From name and From email.
Check personalization tokens.
Check watch, replay, and unsubscribe links.
Check calendar invite behavior if enabled.
Inspect the message in Gmail, Outlook, and a mobile inbox.
Confirm provider logs show accepted delivery.
Confirm no relevant recipients are suppressed in the provider.

After this is done, your automation emails are using the same path attendees will use during launch.