Google Workspace for cold email: limits and a safe setup

Google Workspace is a common choice for cold email, and for a simple reason: your email goes out from the same infrastructure as ordinary business mail, to prospects, many of whom use Google themselves. It doesn't guarantee the inbox, and it's easy to burn a good mailbox by treating Google's limits as a target.

Google's real limits

Google's published limits per user, over a rolling 24 hours, are:

• 2,000 messages a day, or 1,500 through mail merge.
• 3,000 external recipients a day, counting each time a message is sent, and 2,000 unique external recipients.
• 500 messages a day on a trial account, which rises only after the domain has paid at least $100, which can take up to 75 days.

Those limits exist for normal business email. They aren't a safe cold email volume. I use around 30 campaign emails a day per mailbox. Read why that number.

The setup I use

1. Protect your main domain. Never send cold email from it. Buy separate domains close to your brand, and point them to your main site. Check who owns a name first.
2. Three mailboxes per domain. If a domain has trouble, only three mailboxes are affected.
3. Real names. Use a real person's name and a photo. Skip info@ and sales@.
4. SPF, DKIM and DMARC on every domain, plus Google's MX records. The MX lookup and DKIM checker confirm them.
5. About 14 days of warm-up before campaigns start. Here's why.
6. Build volume slowly to about 30 campaign emails a day per mailbox.

How many mailboxes do you need?

Divide the people you want to reach each month by what a mailbox can send, remembering that follow-ups use up sends too. For example, 30 emails a day on about 20 working days is 600 sends a month per mailbox. With one email and three follow-ups, those 600 sends cover 150 new people if everyone gets all four. The mailbox calculator does this for you.

Mistakes that cost you domains

• Using a trial account. Its limits are low, and a brand-new account attracts more suspicion.
• Sending from day one. A mailbox with no history shouldn't jump straight into campaigns.
• Treating a domain as permanent. Sending domains are replaceable. Yours is not.
• Ignoring Google's rules. Read Google's acceptable use policy, and keep your sending relevant, low-volume and easy to opt out of, and read the legal side.

Buy it or set it up yourself?

You can do all of this yourself, and my setup guide walks through it. It takes real time once you have many domains: each needs its own Workspace setup, DNS records and photos. mailzy offers managed Google Workspace mailboxes at $4 per mailbox per month, set up for you, and you can also connect mailboxes you already have. See mailboxes.