Gmail sending limits for cold email (and how to stay under them)

Almost every cold email problem that looks like a deliverability issue is really a sending-limit issue. Google does not warn you before it starts refusing mail, so it is worth knowing the numbers before you plan a campaign.

The limits that matter

Google publishes different limits for different interfaces, and the one that applies to an outreach tool is the SMTP/API limit, not the number you see quoted for the Gmail web interface.

Account type	Recipients per day	Notes
Free Gmail (@gmail.com)	around 500	Counted per recipient, not per message
Google Workspace	around 2,000	Lower for trial and newly created accounts
Workspace trial	often 500 or fewer	Raised once billing is established

Two details catch people out. First, a message to ten recipients counts as ten, not one. Second, the counter is a rolling 24-hour window, not a calendar day, so sending your whole allowance at 11pm does not reset at midnight.

What happens when you go over

Google does not bounce the mail with a clear explanation. You get a temporary failure, usually a 550 or 421 with wording about the limit, and sending stays blocked for up to 24 hours. Repeatedly hitting the ceiling is also a signal Google uses when deciding whether an account is being used for bulk unsolicited mail.

Why you should send far fewer than the limit

The daily limit is a hard ceiling, not a target. Cold outreach has a different shape from normal mail — many recipients who have never replied to you, often at similar times — and sending close to the ceiling makes that pattern obvious.

A new mailbox should start at 10 to 20 a day and increase gradually over several weeks. An established mailbox sending 50 to 100 a day is unremarkable. The precise number matters less than the fact that it is steady: a mailbox that sends 20 a day for a month looks far better than one that sends 400 on a Monday and nothing else.

Using more than one mailbox

The usual way to send more is to add mailboxes rather than push one harder. Each one carries its own limit and its own reputation, so a problem with one does not stop the rest. The trade-off is that every mailbox needs its own warm-up period and its own authentication records.

How RichLead handles this

Each connected mailbox has a daily send limit you set, and RichLead counts against it and stops rather than letting a campaign run into Google's ceiling. The Deliverability page shows what each mailbox has used today and what is left, so you can see which one has room before you approve a batch.

If you connect more than one mailbox, sends are spread across them rather than concentrated on the first one.

A short checklist

• Know which limit applies to your account type, and remember it counts recipients.
• Set a daily cap in your tool that is well under it.
• Start low on a new mailbox and raise it over weeks, not days.
• Add mailboxes to scale, rather than pushing one to its ceiling.
• Watch for 421 and 550 responses — they are the early warning.