Active Domain Names By Provider
| Provider | Domain Names | MX Record |
|---|---|---|
| Forward Email | 418,477 | mx1.forwardemail.net |
| Proton Mail | 253,977 |
mail.protonmail.ch |
| Fastmail | 168,433 |
in1-smtp.messagingengine.com |
| Mailbox | 38,659 |
mxext1.mailbox.org |
| Tuta | 18,781 |
mail.tutanota.de |
| Skiff | 7,504 |
inbound-smtp.skiff.com |
As you can see, we are the leading custom domain email provider (other than Gmail and Outlook of course) vs. any similar competitor. You can see we are trusted at a large scale already.
Source: Security Trails reverse MX search as of January 5, 2024.