Requirements:

• OpenBSD iso support out of the box (or with minimal configurations)
• 1GB RAM
• Static IP + reverse dns configuration
• Allows opening email ports
• AES-NI (for hardware accelerated cryptography)

NOTE: Also add any known limitations and cons to each network, if it has been generally experienced by users.

Excision Mail uses: https://vultr.com