Table of contents
Technical setup

SMTP Setup for Cold Email: Send from Your Own Domain

JacSend sends through your SMTP - not a shared platform domain. Here is how to connect your inbox, authenticate your domain, and protect deliverability for cold outreach.

10 min readUpdated June 2026

Professional cold email outreach sends from an address you control - typically you@yourcompany.com on a domain with proper authentication. JacSend uses nodemailer to deliver through your SMTP credentials, so recipients see mail from you, not from a third-party sending subdomain.

This guide walks through SMTP setup options, authentication records, and how to connect your mail server in JacSend Settings before activating a campaign.

Why JacSend requires your own SMTP

Shared sending domains pool reputation across thousands of users. One bad actor can hurt everyone. When you send cold outreach from your SMTP, deliverability reflects your list quality and copy - and you build long-term domain authority for your brand.

JacSend never sends live outreach from a platform-owned domain. Preview drafts work without SMTP; actual sends require a connected mail server in Settings.

SMTP provider options for outreach

Common choices include Google Workspace, Microsoft 365, Zoho, Fastmail, and transactional providers configured for SMTP relay. Many founders use a dedicated outreach alias like hello@ or alex@ on their primary domain, or a secondary domain for outbound.

  • Google Workspace: smtp.gmail.com with app password or OAuth where supported
  • Microsoft 365: smtp.office365.com with modern auth policies
  • Custom domain on transactional SMTP: Mailgun, SendGrid, Amazon SES (check their cold email policies)
  • Dedicated outreach subdomain: outreach.yourcompany.com with full DNS auth

SPF, DKIM, and DMARC for deliverability

Email providers verify that sending servers are authorized for your domain. SPF lists allowed senders. DKIM cryptographically signs messages. DMARC tells receivers how to handle failures.

Configure all three before scaling cold outreach. Missing authentication is one of the fastest paths to spam folders regardless of copy quality.

Connecting SMTP in JacSend

Open Settings in JacSend and enter your SMTP host, port, username, password or app-specific password, and from name. JacSend encrypts credentials at rest. Test with Send now on a small campaign before activating full sequences.

If sends fail, verify firewall rules, two-factor app passwords, and that your provider allows SMTP from server IPs (some block datacenter ranges - check provider docs).

Security and credential hygiene

Use app passwords instead of your primary account password. Restrict SMTP users to send-only roles where possible. Rotate credentials if compromised. JacSend stores encrypted SMTP secrets and never exposes them in the client.

Domain warmup before high volume

New domains and fresh inboxes should ramp volume slowly - start with JacSend's free 5 sends, then scale through Starter and Pro plans as engagement proves out. Pair warmup with targeted lists and strong copy, not purchased contacts.

Frequently asked questions

Can I use JacSend without SMTP?
Yes for AI draft previews and campaign setup. Live sending and automated follow-ups require a connected SMTP server in Settings.
Does JacSend work with Gmail?
Yes, with Google Workspace or Gmail SMTP using an app password where Google allows SMTP access. Check Google's current policies for your account type.
What SMTP port should I use?
Port 587 with STARTTLS is standard. Port 465 with SSL works for some providers. JacSend supports common configurations - refer to your provider's documentation.
Will cold email hurt my primary domain?
It can if you send low-quality mail at high volume. Many teams use a dedicated subdomain or alias, keep volumes modest, and monitor bounces. JacSend's limits encourage sustainable sending.
Is my SMTP password stored securely?
JacSend encrypts SMTP credentials at rest using your deployment's encryption key. Never share production ENCRYPTION_KEY or commit secrets to version control.

Try JacSend for your next campaign

Import contacts, preview AI drafts in your voice, connect your SMTP, and automate a proven 4-touch follow-up sequence. Start free with 5 sends included.