SEmail Deliverability Glossary

Sending Limits (Daily Sending Limits)

Caps on the number of emails that can be sent per day from an account, IP, or domain. Warm-up ramp-up schedules must stay within these limits at all times.

Sending limits are caps on the number of emails that can be sent per day, hour, or minute from a given account, IP, or domain. They are enforced by ESPs, ISPs, and Google/Microsoft for their own accounts.

Gmail sending limits (2024):

Free Gmail: 500 emails/day
Google Workspace: 2,000 emails/day (standard), 10,000 via SMTP relay

How limits affect warm-up:

Your warm-up ramp-up schedule must respect the sending limits of your email infrastructure. Attempting to send beyond your ESP or platform limits during warm-up can trigger account suspension.

Why exceeding limits damages reputation: ISPs interpret sudden surges past your historical sending pattern as anomalous. Even if the ESP allows the volume, ISPs may filter more aggressively when volume spikes unexpectedly.

Frequently Asked Questions

What are Gmail's daily sending limits?

Free Gmail accounts can send up to 500 emails per day via the Gmail interface or API. Google Workspace accounts can send 2,000 emails per day via the standard Gmail interface, or up to 10,000 per day when routing through Google's SMTP relay service. These limits reset every 24 hours. For high-volume cold email, Google Workspace accounts are commonly used but quickly hit their daily limits at scale — most serious cold email senders use purpose-built cold email ESPs (Instantly, Smartlead, etc.) with dedicated infrastructure that supports higher volumes.

What happens if I exceed my ESP's sending limits during warm-up?

Exceeding sending limits typically triggers two problems: your ESP may throttle or temporarily suspend your account, and the sudden volume spike registers as anomalous behavior with ISPs even if the emails technically send. Most ESPs enforce limits with a soft cap (slowing delivery when you approach the limit) and a hard cap (rejecting sends above the limit). Exceeding limits consistently may result in your account being flagged for review. Always check your ESP's daily, hourly, and per-minute limits before designing your warm-up ramp schedule and ensure your ramp stays comfortably within those constraints.

How do sending limits interact with email warm-up timing?

Sending limits create a ceiling your warm-up schedule must respect. If your Gmail Workspace account allows 2,000 emails/day, your warm-up ramp-up can approach but never exceed that number. For the warm-up tool sends combined with any manual sends you make from the same account, the combined total must stay within the daily limit. Inboxwarm.ai accounts for your sending limits when scheduling warm-up traffic, ensuring the tool's sends plus any sends you initiate stay within safe thresholds. If you're approaching your account's limit regularly, it's a signal to upgrade your sending infrastructure rather than try to work around the limit.

Related Terms

Email Volume Ramp-Up

The planned, gradual increase in sending volume during warm-up — giving ISPs time to observe positive behavior before large volumes are introduced.

ESP (Email Service Provider)

A platform providing email sending infrastructure and campaign tools — e.g., Mailchimp, SendGrid, Instantly, Lemlist. ESP choice affects your warm-up strategy.

Dedicated IP

An IP address used exclusively by a single sender. Gives full reputation control but requires complete warm-up from zero before high-volume sending.

IP Warm-Up

The process of gradually increasing sending volume from a new IP address to build positive ISP reputation before scaling to full send volume.

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