You ssh'd into a fresh Linux box and you need to send an email. Maybe a backup completed. Maybe a deploy succeeded. Maybe a process crashed and you want a stack trace in your inbox.

The traditional path: install Postfix, edit main.cf, configure a smart relay, generate SASL credentials, restart the daemon, and pray nothing else on the box uses port 25. That is the 30-minute path.

The 60-second path:

curl -fsSL https://cli.nylas.com/install.sh | bash
~/.config/nylas/bin/nylas auth config --api-key YOUR_KEY
~/.config/nylas/bin/nylas email send --to you@example.com --subject hi --body "From $(hostname)"

Three lines. Zero daemon. Works on every modern Linux distro and macOS.

Why the old path is so slow

Setting up outbound SMTP from scratch involves five separate concerns:

Five places to get it wrong. Most people get it wrong twice before it works.

What the 60-second path skips

The CLI ships a static binary. No package dependencies, no system services, no firewall punches. The send happens over HTTPS to the Nylas API on port 443 — already open in 99% of environments.

Specifically, you are not:

• Opening port 25 outbound (most cloud providers block this)
• Setting up STARTTLS to a relay
• Maintaining sender DKIM/SPF/DMARC keys (the API handles signing)
• Writing config files in /etc/postfix

Real-world recipes

Cron job that emails on failure

#!/usr/bin/env bash
if /usr/local/bin/run-backup.sh; then
  exit 0
fi

nylas email send --to oncall@yourcompany.com \
  --subject "[FAIL] backup on $(hostname)" \
  --body "$(date): backup failed. See /var/log/backup.log"

systemd OnFailure handler

# /etc/systemd/system/notify-failure@.service
[Unit]
Description=Notify on service failure for %i

[Service]
Type=oneshot
ExecStart=/usr/local/bin/nylas email send --to oncall@yourcompany.com \
  --subject "[%H] %i failed" \
  --body "Check journalctl -u %i for details"

# In any service that should notify on failure:
[Unit]
OnFailure=notify-failure@%n.service

This is exactly the pattern the systemd man pages document for OnFailure, with one less moving part.

Deploy notification from CI

nylas email send --to team@yourcompany.com \
  --subject "✅ Deploy v${VERSION} to prod" \
  --body "https://app.example.com/deploys/${DEPLOY_ID}"

Shell trap on script exit

trap 'nylas email send --to me@example.com --subject "rebuild done on $(hostname)" --body "exit code $?"' EXIT

./long-running-rebuild.sh

What about mailx, msmtp, sendmail?

They are venerable, and on a single machine where you already have a working relay, they are fine. Where they hurt:

• mailx needs an MTA underneath (Postfix, Exim). Nothing changes about the SMTP setup.
• msmtp is itself an SMTP client, so you still maintain relay credentials and TLS.
• sendmail is the historical command, usually backed by Postfix.

The Nylas CLI replaces all three for the "I need to send from a script" use case. There is no relay to maintain because the relay is the API.

The 60-second checklist

# 1. Install
curl -fsSL https://cli.nylas.com/install.sh | bash

# 2. Add to PATH for the session
export PATH="$HOME/.config/nylas/bin:$PATH"

# 3. Auth
nylas auth config --api-key YOUR_KEY

# 4. Test
nylas email send --to you@example.com --subject hi --body "from $(hostname)"

# 5. Verify it landed (should be in your inbox in <30 sec)

If step 5 worked, you are done. Add the binary location to a system-wide PATH (e.g., symlink to /usr/local/bin) if other users on the box need it.

A note for hardened environments

If your server has no outbound HTTPS — air-gapped, restricted egress firewall — the CLI cannot reach the API. In that case, ship messages to an internal queue (or a relay box that does have egress) and let that machine call the CLI. The CLI itself is not the bottleneck; outbound HTTPS is.

Otherwise, this is the cleanest "make this Linux box send mail" setup I have used.

Next steps

• Send email from the terminal — full nylas email send reference
• Best CLI email tools compared — head-to-head with mutt, mailx, msmtp
• PowerShell email reports — same idea on Windows
• Full command reference