Mailchannels or other SMTP smart host

Questions
1

Your question

Hello,

I am impressed by JMAP and this software in general, and would love to try it out and maybe even use it in production. But before I do so, I was never into sending emails from my IPs due to numerous reasons, so I always used MailChannels.

Would a smarthost like that be compatible with Stalwart, or am I limited to SMTP via my own infrastructure without access to something like EXIM configurations :slight_smile:

Thank you!

All the best :smiley:

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on

2

Yes, Stalwart fully supports smart-host relaying, MailChannels included. You define a Relay-type MtaRoute object pointing at the smart host’s address/port, with optional TLS and SMTP AUTH credentials, and then use the outbound routing expression on MtaOutboundStrategy to send all (or selected) outbound mail through it instead of resolving MX records directly.

Example relay route:

{
  "@type": "Relay",
  "name": "relay",
  "address": "relay.mailchannels.net",
  "port": 587,
  "protocol": "smtp",
  "implicitTls": false,
  "authUsername": "your-username",
  "authSecret": {"@type": "Value", "secret": "your-password"}
}

You then set the routing strategy’s expression (e.g. always resolve to 'relay', or only for certain domains) to select this route. This is configured via the WebUI (Settings › MTA › Outbound › Routes) or through stalwart-cli/JMAP, not via Exim-style config files. See the docs on outbound routing.

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