Email setup · Works with an app password; enter the server yourself.

Connect Fastmail to Revnio

Revnio does not have a Fastmail shortcut, so you enter the server details yourself under “Advanced settings”. You also need an app password from Fastmail.

Last checked October 24, 2026. Providers change their menus, so if a button is missing, use the official links at the bottom of this page.

Before you start

A Fastmail plan that allows sending from other apps. One Fastmail help page reportedly says Basic plans do not include SMTP access, so check yours.

Step by step

In Fastmail, open Settings, then Privacy & Security, then Integrations, and choose to create a new app password. Give it SMTP (mail sending) access.
Name it “Revnio” and copy the password.
In Revnio, open “Any email account” and enter your Fastmail address. Revnio will say it does not recognize the provider, which is fine.
In Advanced settings enter: server smtp.fastmail.com, port 465, security SSL.
Paste the app password and click “Connect and send me a test email”.

Server settings

Revnio fills these in when it recognizes your provider. Enter them yourself under Advanced settings if it does not.

Server	`smtp.fastmail.com`
Port	465 (SSL) or 587 (STARTTLS)
Security	SSL or STARTTLS
Username	Your full Fastmail address

If it doesn’t work

Login rejected. Use the app password with SMTP access, not your Fastmail login password.
Secure connection failed. Try port 587 with STARTTLS instead of 465 with SSL.

Taking the access back

Delete the app password in Fastmail’s Privacy & Security settings, and click Disconnect in Revnio.

Sending limits

Not documented in the sources we could check. Revnio’s cap for mailboxes without a built-in shortcut is 200 a day. Revnio stops sending through your mailbox once it has sent this many recovery emails in 24 hours, and sends the rest through Revnio’s own sender so nothing is delayed. These caps are conservative Revnio defaults, not limits set by the provider.

What we could not confirm

We checked this page against the provider’s own help where we could find it. These details we could not confirm from an official source, so check them with your provider:

The exact Settings menu path and button names: sources We found are third-party guides.
Which Fastmail plans include SMTP access.
Sending limits.

Official sources

Frequently asked questions

What is an app password?

An app password is a separate, one-purpose password that your email provider creates for a single program. Revnio uses it to send recovery emails from your mailbox, and your real password never goes into Revnio. Most providers require one when two-step verification is on.

Why can’t I just use my normal email password?

Many providers (Google, Yahoo and Apple among them) block outside programs from signing in with your everyday password. They ask for an app password so that you can cancel Revnio’s access later without changing your real password.

Is it safe? What does Revnio do with the password?

Revnio stores the password encrypted and never shows it back to you or to anyone else in the dashboard. Only an admin can connect a mailbox, and disconnecting deletes the stored password. An app password can open your mailbox, so treat it like a password: give it a name you recognize and delete it when you stop using Revnio.

Can I revoke it later?

Yes. Delete the app password with your email provider (each provider’s page shows where) and click Disconnect in Revnio. For the one-click Gmail connection, Disconnect also tells Google to end Revnio’s access.

Which mailbox is used if I connect more than one?

One mailbox per organization. Connecting a new one replaces the old one, and the dashboard asks you to confirm before it does.

Recover failed payments on autopilot

Revnio retries failed payments at the right time and reaches customers by email and WhatsApp until the card is fixed. Works with Stripe, Chargebee and Paddle.

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