BooleanSMTP posts a Discord message the moment an outgoing email finally fails to send. Setup uses a Discord webhook you create yourself — BooleanSMTP only ever sees the webhook URL you paste in. There is no bot to create and no ID to look up: the webhook URL already identifies the destination channel.
Create a Discord webhook
- In Discord, open the server and channel you want alerts posted into.
- Open that channel’s settings and go to Integrations → Webhooks.
- Click New Webhook, give it a name (for example “BooleanSMTP Alerts”), and confirm the target channel.
- Click Copy Webhook URL. It looks like
https://discord.com/api/webhooks/123456789012345678/AbCdEfGh.... Anyone with this URL can post messages into that channel, so keep it private.
Connect Discord in BooleanSMTP
- In the BooleanSMTP sidebar, click Alerts.
- Find Discord in the provider list and click Set up.
- Under Settings, paste the URL you copied into Webhook URL.
- Webhook display name is optional. It changes the sender name Discord shows on each alert message — it does not change which channel the alert posts to. Leave it blank to use “BooleanSMTP”.
- Leave This webhook URL is proxied through a third-party relay unchecked, unless you are intentionally routing the webhook through your own proxy instead of pointing straight at Discord. Checking it accepts any HTTPS URL instead of just Discord’s own domain.
Send a test alert
- Leave Send alerts on. BooleanSMTP does not send real alerts through a provider that is off.
- Click Send Test. BooleanSMTP posts a real message to Discord using the values currently in the form.
- Click Save.
A failed test shows Discord’s own error text, not just “failed” — see below for what the common ones mean.
Common errors
“Discord Webhook URL is required.” — the Webhook URL field is empty.
“This does not look like a Discord webhook URL.” — the URL doesn’t match Discord’s webhook shape. Check you copied the full URL from Discord’s Copy Webhook URL button, not a different service’s webhook — or check This webhook URL is proxied through a third-party relay if you’re intentionally using a proxy.
“Unknown Webhook” — the webhook was deleted or regenerated in Discord’s channel settings. Create a new webhook and update the URL here.
A rate-limit message (“You are being rate limited”) — Discord is rate-limiting this webhook. This is rare for normal alert volume; if you see it often, several sites are likely sharing one webhook — create a separate webhook per site.
Send Test worked, but no alerts arrive — confirm Send alerts is on and you clicked Save.
Alerts arrive in the wrong channel — the webhook URL fixes the destination channel in Discord; there’s no separate channel selector in BooleanSMTP. Create a new webhook against the right channel and update the URL here.
See also: Alerts, Slack alerts, Telegram alerts.