Integration
Send Invoices with Resend
Connect Resend's modern email API to send professional invoices and quotations with PDF attachments. High deliverability, free tier included.
Why use Resend for invoicing?
High Deliverability
Resend uses dedicated IPs and proper authentication (SPF, DKIM, DMARC) so your invoices land in the inbox, not spam.
3,000 Free Emails/mo
The free tier is generous enough for most small businesses. Send up to 100 invoices per day at no cost.
PDF Attachments
Every invoice and quotation email includes a professionally formatted PDF using your selected template.
2-Minute Setup
Create an account, get an API key, paste it in settings. No complex SMTP configuration needed.
Step-by-Step Setup Guide
Create a Resend Account
Go to resend.com/signup and create a free account. The free tier includes 3,000 emails/month and 100 emails/day — enough for most small businesses.
Generate an API Key
In the Resend dashboard, navigate to API Keys in the left sidebar. Click Create API Key, enter a name like "Invoice Maker", select Full access permission, and click Add. Copy the key that starts with re_.
Add Your Domain (Recommended)
For professional emails from your own address (e.g. invoices@yourbusiness.com), go to Domains in Resend and add your domain. You will need to add DNS records (MX, SPF, DKIM) — Resend guides you through each step. Verification takes 5-10 minutes. Without a custom domain, emails send from onboarding@resend.dev.
Configure in Invoice Maker
Log in to your dashboard, go to Settings → Email. Select Resend as your email provider, paste your API key, optionally add your verified "From Email" address, set your business name, and click Save Email Settings.
Send a Test Email
Below the settings, enter your own email address and click Send Test. You should receive a confirmation email within seconds. If it works, you are all set to email invoices and quotations to your customers!
What your customers receive
Professional Email
Beautiful HTML email with invoice number, amount, due date, and your business branding.
PDF Attachment
Invoice PDF auto-attached using your chosen template (A4 Classic, Modern, Professional, etc.).
Status Tracking
Invoice automatically marked as "Sent" in your dashboard after successful delivery.
Resend vs Gmail vs Custom SMTP
| Feature | Resend | Gmail | Custom SMTP |
|---|---|---|---|
| Setup time | 2 minutes | 5 minutes | 10+ minutes |
| Free emails/month | 3,000 | ~500/day | Varies by provider |
| Custom domain | Yes (verified) | No (Gmail only) | Yes |
| PDF attachments | Yes | Yes | Yes |
| Delivery tracking | Yes | No | Depends |
| 2FA/App Password | Not needed | Required | Depends |
| Best for | Growing businesses | Personal use | Technical teams |
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Frequently asked questions
Everything you need to know about our free online invoice maker