# Receive email


Your VM can receive emails at `*@vmname.exe.xyz`.

## Enable

```bash
ssh exe.dev share receive-email vmname on
```

Once enabled, any email sent to `any.name.here@vmname.exe.xyz` will be delivered to `~/Maildir/new/` on your VM.

Enabling inbound email also lets your VM reply to the people who email it,
scoped to their threads by default; see
[replying to correspondents](/docs/send-email#replying-to-people-who-email-your-vm),
including the `--reply-policy` flag to restrict or disable this.

## Disable

```bash
ssh exe.dev share receive-email vmname off
```

Disabling does not delete existing emails. It does clear the VM's permission
to reply to people who have emailed it — except that anyone who unsubscribed
stays unsubscribed.

## Email format

Emails are delivered in [Maildir format](https://en.wikipedia.org/wiki/Maildir).

Email include an injected `Delivered-To:` header as the first line, containing the envelope recipient address. Use this header (not `To:` or `CC:`) to determine what address the email was sent to.

`DKIM-Signature:` headers are removed before delivery. exe.dev checks them on the message as it arrived, and what it concludes is what decides who your VM may reply to. A signature is a reusable credential — anyone holding a signed message can present it again — so your VM gets the mail without it, and cannot re-present someone else's mail as permission. Other authentication headers, such as `Authentication-Results:`, are passed through untouched; they are the upstream relay's claims, and exe.dev does not trust them either.

To watch for new mail, poll or use inotify. For example:

```bash
inotifywait -m ~/Maildir/new -e create -e moved_to |
  while read dir action file; do
    FILE="$dir/$file"
    # process email in $FILE
    mv "$FILE" ~/Maildir/cur/
  done
```

You are responsible for promptly moving emails out of `~/Maildir/new/`. If there are more than 1000 files in that directory, we will automatically disable email receiving. If this happens, you may clear the backlog and re-enable it, as above.

## Limitations

- No spam, virus, phishing, or safety checks, we only deliver the bits
- No custom domains yet, only `*.exe.xyz`
- Strict receiving rules; mail that fails authentication may be rejected
- 1MB maximum message size
- Delivered emails must be processed promptly