You have a list of businesses to email and one question blocking you: do you send through a Gmail account or plug in an SMTP server? Pick wrong and you either hit sending limits, land in spam, or put your main business domain at risk.
This guide helps you choose in a few minutes and then set things up properly.
The short answer
For most small businesses, freelancers and agencies starting cold outreach, Google Workspace (paid Gmail on your own domain) is the simpler choice. It is familiar, replies land in a normal inbox, and setup takes an afternoon.
SMTP makes sense when you already use a different email host (Microsoft 365, Zoho, your web host), when you want to spread sending across several providers, or when you are an agency managing many client mailboxes.
One thing to rule out: a free @gmail.com address. It does not show your brand, you cannot set up your own domain authentication, and Google's terms are not built for bulk outreach. Use a domain you own.
How the two options actually differ
"SMTP" is just the protocol that sends email. Gmail uses it too. The real choice is between connecting a Google account directly (usually via sign-in) or entering server details from any provider.
| Google Workspace (Gmail) | Other provider via SMTP | |
|---|---|---|
| Setup | Sign in, approve access | Enter host, port, username, password |
| Replies | Normal Gmail inbox | That provider's inbox |
| Daily limits | Set by Google, check current limits | Set by each provider, varies widely |
| Best for | One business, a few mailboxes | Existing non-Google email, agencies, mixed providers |
Neither option fixes bad deliverability on its own. Your domain setup, list quality and sending volume matter more than which button you click. See email deliverability for the bigger picture.
Step 1: Get a separate sending domain
Do not send cold email from the domain your customers and invoices use. If it gets flagged, your everyday email suffers.
- Buy a domain close to your brand, for example yourbrand-mail.com or getyourbrand.com.
- Point its website to your main site with a redirect, so curious recipients find you.
- Create one or two mailboxes on it with real names, like anna@.
As a rule of thumb, start with one or two mailboxes and add more only when you need more volume.
Step 2: Set up authentication records
Whichever route you pick, add these DNS records at your domain registrar. Your email provider gives you the exact values.
- SPF: lists which servers may send for your domain.
- DKIM: signs your messages so receivers can verify them. Turn it on inside Workspace admin or your SMTP provider.
- DMARC: tells receivers what to do with mail that fails checks. Start with a monitoring policy (p=none) and tighten later.
Major mailbox providers have published sender requirements around authentication and easy unsubscribing. Check the current rules for the providers your prospects use.
Step 3: Connect the account
For Gmail / Workspace: in your sending tool, choose Google, sign in with the new mailbox and approve access. Send a test to yourself and a friend on a different provider.
For SMTP: find your provider's SMTP settings (host, port, usually 587 with TLS or 465 with SSL) and create an app password if two-factor login is on. Enter them, send a test, and confirm replies arrive where you expect.
In GetClient you can connect Gmail accounts or any SMTP account, and replies from all of them show up in one Inbox, so mixing both is fine.
Step 4: Start slow and keep volume modest
A brand new mailbox sending a few hundred emails on day one looks suspicious. A sensible rule of thumb:
- Week 1: a handful of real, personal emails per day.
- Then raise volume gradually, watching replies and bounces.
- Keep cold sends per mailbox well below the provider's hard limit.
Need more volume? Add mailboxes instead of pushing one harder. Spread sends across weekdays and skip days your audience will not read email.
Step 5: Clean the list before you send
Bounces hurt your sender reputation fast, regardless of Gmail or SMTP. Verify every address first and remove role inboxes that never reply. Read up on email bounce rate to know what to watch.
If you build lists from Google Maps, GetClient lets you scrape leads, verify the emails and send the campaign from the same place, so you are not exporting CSVs between three tools. You can start with free credits; details are on pricing.
Step 6: Write and schedule a short sequence
Keep the first email short and specific to the business. Use merge tags like {{params.name}} and {{params.city}} so each message reads like it was written for them. Plan two or three follow-ups a few days apart, and include a clear unsubscribe link. Our guide to a follow-up sequence covers timing and wording.
Quick decision checklist
- Already on Google Workspace or starting fresh? Use Gmail.
- Already on Microsoft 365, Zoho or another host? Use SMTP with that provider.
- Running outreach for several clients? Use whatever each client's domain runs on, connected via SMTP or Google.
- Either way: separate domain, SPF/DKIM/DMARC, slow start, verified list.