Frequently asked questions

Common questions about using Zapmail temporary email service

General questions

How long are emails stored?

Emails are automatically stored for 7 days from the time they are received. After this period, they are permanently deleted by the automated cleanup job that runs hourly.

The cleanup job removes all emails where received_at < NOW() - INTERVAL '7 days' from the database. This ensures your temporary emails don’t persist indefinitely.

If you need to keep important information from a temporary email, make sure to save it elsewhere before the 7-day retention period expires.

Is Zapmail secure and private?

Zapmail provides temporary email addresses for short-term use. Here’s what you should know about security:

What Zapmail does:

• Stores emails in an encrypted PostgreSQL database (Supabase)
• Automatically purges emails after 7 days
• Uses secure SMTP protocol for receiving messages
• Processes all connections in isolated goroutines

What Zapmail doesn’t provide:

• End-to-end encryption for email contents
• Authentication or password protection for addresses
• Permanent email storage

Anyone who knows your temporary email address can view emails sent to it. Never use temporary email addresses for sensitive communications like banking, medical records, or confidential business.

Can I reply to emails I receive?

No, Zapmail is a receive-only email service. You cannot send or reply to emails from your temporary address.

The SMTP server in backend/main.go:38-62 is configured to accept incoming connections only. If you need to reply to a sender, you’ll need to use a different email service.

Zapmail is designed for situations where you need to receive verification emails, newsletters, or one-time communications without exposing your personal email address.

How do I get a temporary email address?

Getting a temporary email address with Zapmail is simple:

1. Visit the Zapmail homepage
2. Click the “Generate Email” button
3. Your temporary address will be created instantly (format: [e-mail])
4. Copy the address to use wherever you need it
5. Return to Zapmail to check your inbox

No registration, login, or personal information required. The address is ready to receive emails immediately.

How many emails can I receive?

There is no hard limit on the number of emails you can receive at a single temporary address. The SMTP server (backend/main.go:65-160) processes each incoming email and stores it in the database.

However, all emails are subject to the 7-day retention policy. The system is designed for temporary, short-term email needs rather than high-volume or long-term storage.

Can I use custom usernames?

This depends on your Zapmail deployment configuration. The backend extracts the username from the recipient address using the format before the @ symbol (backend/main.go:163-170).

Check with your instance administrator to see if custom usernames are supported, or if addresses are randomly generated.

What email formats are supported?

Zapmail accepts standard email formats including:

• Plain text emails
• HTML emails
• Emails with attachments
• Multi-part MIME messages

The server stores the complete raw email data (backend/main.go:131-143), which is then parsed and displayed in the web interface.

How often does the inbox refresh?

The Next.js frontend typically polls for new emails at regular intervals. Check your browser’s network tab to see the refresh rate, or manually refresh the page to check for new messages.

Emails are stored in the database immediately upon receipt by the SMTP server, so there’s no delay on the backend.

Technical questions

What SMTP commands does Zapmail support?

Zapmail implements the core SMTP protocol with the following commands:

Command	Description	Response Code
HELO / EHLO	Initiate connection	250 Hello
MAIL FROM	Specify sender address	250 Sender OK
RCPT TO	Specify recipient address	250 Recipient OK
DATA	Begin message transmission	354 End data with <CR><LF>.<CR><LF>
QUIT	Close connection	221 Bye
NOOP	No operation	250 OK
HELP	List supported commands	214 Commands supported
VRFY	Verify address (not supported)	250 VRFY not supported
EXPN	Expand mailing list (not supported)	250 EXPN not supported

See backend/main.go:92-159 for the complete command implementation.

Which port does the SMTP server use?

The SMTP server port is configured via the PORT environment variable (backend/main.go:40-43). Common configurations:

• Port 2525 (common for development)
• Port 25 (standard SMTP, may require root privileges)
• Port 587 (submission port)

Check your deployment’s environment configuration to see which port is in use.

How does the cleanup job work?

The cleanup job is a background goroutine that starts when the SMTP server launches (backend/main.go:196-208).

Cleanup process:

1. Runs every hour (configurable via time.NewTicker(1 * time.Hour))
2. Executes SQL: DELETE FROM emails WHERE received_at < NOW() - INTERVAL '7 days'
3. Logs the result of each cleanup operation

This ensures the database doesn’t grow indefinitely and maintains the temporary nature of the service.

What database does Zapmail use?

Zapmail uses PostgreSQL via Supabase, configured through the SUPABASE_CONN_STRING environment variable (backend/main.go:173-183).

The database schema includes an emails table with columns:

• id - Primary key
• username - Extracted from recipient address
• recipient - Full recipient email address
• raw_data - Complete email content
• received_at - Timestamp of when email was received