I would be cautious with both. The main concerns:

1. Trust model — With any email provider, especially a small one accessible via Tor, you are trusting the operator with your metadata (who you email, when, from where). A .onion address does not magically make this trustworthy.

2. Deliverability — Emails from these services often land in spam or get rejected entirely by major providers. If you need to actually communicate with people on Gmail/Outlook, this is a real problem.

3. Longevity — Small Tor-based email services come and go. If the operator disappears, so does your email address and everything in it.

Better alternatives for privacy-focused email:

• Proton Mail (free tier, E2EE, established track record, .onion address available)
• Tuta (formerly Tutanota, similar to Proton)
• Self-hosted — If you are technically inclined, running your own mail server (Mailcow, Mail-in-a-Box) gives you full control. It is more work but you own everything.

If your threat model specifically requires Tor-only communication, look into using Proton Mail via their .onion address, or use XMPP/Matrix over Tor instead of email entirely.