We believe in being limitless wherever we can. But every email service worth trusting has a few guardrails in place, and ours exist for a single reason: to protect the deliverability of every sender on our network.
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Quick Reference: Every SMTP2GO Sending Limit
| Limit | Value | Applies to |
|---|---|---|
| Free plan monthly allowance | 1,000 emails | Free accounts |
| Free plan daily cap | 200 emails | Free accounts |
| Free plan hourly cap | 25 emails (lifted when sender domain is verified) | Free accounts |
| Paid plan monthly allowance | 10K, 100K, or custom (Premier) | Starter, Professional, Premier |
| Overage allowance | Up to 3x your monthly plan, billed per thousand | All paid plans |
| Probation cap (new paid accounts) | 1,000 emails per day until review is complete | New paid accounts |
| Default maximum sending speed | 200,000 emails per hour | All accounts (request increase anytime) |
| Emails per SMTP session | 5,000 | All accounts |
| Concurrent SMTP connections | 40 | All accounts |
| SMTP user rate limit | Optional, set by you | Per SMTP user |
If a number on this list is the only thing you came for, you are done. If you want to know why a limit exists or how to lift it, keep reading.
Why We Have Sending Limits
A shared sending platform is, by definition, a shared reputation. If one sender on our network blasts a million unverified addresses overnight, every other sender feels the deliverability hit when mailbox providers respond. Limits stop that from happening.
They also do three quieter, more useful things:
- They protect new senders from themselves. The first 30 days of any sending program are the most fragile. Going from zero to 200,000 emails on day one is the fastest way to land in the spam folder forever.
- They keep our infrastructure fast for everyone. Concurrency caps and per-session limits mean no single account can starve the queue.
- They give you early warning. Most of our limits trigger notifications well before you hit them, so a bad list or a runaway script gets caught before it costs you.
If you are new to deliverability concepts, our guide on how to improve email deliverability is the right next read.
Free Plan Sending Limits
Free SMTP2GO accounts can send:
- 1,000 emails per month
- 200 emails per day
- 25 emails per hour (this hourly cap is removed automatically once you verify your sender domain)
The free plan is built for testing, side projects, and small production workloads. It is not throttled or time-limited. Use it as long as it fits.
If you exceed your free allowance, sending stops. Emails are not queued for the next month, they are rejected at the server. We send notifications well before you get there (more on that below).
Paid Plan Sending Limits
Paid plans are sized by monthly allowance, with the same engine and deliverability features behind every tier. From our pricing page:
- Starter: 10,000 emails/month
- Professional: 100,000 emails/month, includes a dedicated IP
- Premier: Custom volumes above 3 million/month
Two things make paid plans flexible in a way most senders appreciate:
1. The 3x overage allowance. Every paid account can send up to three times its monthly limit when a campaign or seasonal spike demands it. Overage is billed per thousand at the rate listed for your plan. So if you are on Starter and a launch month doubles your volume, you keep sending. Nothing stops.
2. No hourly cap on paid plans. The free plan hourly cap goes away the moment you upgrade (or verify your sender domain on free). Paid accounts are governed by the maximum sending speed instead, which we cover next.
Probation Period for New Paid Accounts
Every new paid account goes through a one-time review process. During probation, sending is capped at 1,000 emails per day. Anything beyond that is held in queue and released the next day, or as soon as your account is fully activated.
Probation is short, usually a matter of hours to a day or two for legitimate senders. It exists because we operate a strict anti-abuse policy, and that policy is the reason our IPs stay off blacklists. Full details are in our probation knowledge base article.
If your launch timing is tight, contact support and let us know. We can usually expedite.
Maximum Sending Speed
The default maximum sending speed is 200,000 emails per hour per account. Inside that envelope, two technical caps shape how the throughput is delivered:
- 5,000 emails per SMTP session
- 40 simultaneous (concurrent) connections
For most senders, 200,000/hour is more headroom than they will ever use. For senders who actually need more, we lift it. Just message support, tell us your target volume, and we adjust the cap. Higher speeds typically pair with a dedicated IP and, if you are scaling fast, a warm-up plan.
If your sending feels slower than your plan should allow, the issue is usually a misconfigured client rather than our limits. We covered the common causes in this troubleshooting guide on slow sending speeds.
SMTP User Rate Limits
Inside any SMTP2GO account, you can create individual SMTP users (each with its own credentials) for different apps, departments, or clients. As the account owner, you choose whether each user has a rate limit or unlimited sending.
The single most useful thing to understand: a rate limit is a speed limit, not a bucket. A user limited to 100 emails per hour is not allowed to fire all 100 in the first second and then sit idle. That same limit translates to roughly 1.6 emails per minute, or three emails every two minutes. Exceed that pace and individual emails get rejected at the server, even though the hour is not “full.”
Setting per-user limits is optional but recommended whenever you have multiple apps or third parties sending through the same account. It keeps a runaway script in one corner from chewing through your monthly allowance.
What Happens When You Hit a Limit
Three different outcomes, depending on which limit you hit:
- Monthly allowance reached: sending stops at 100% (or at 300% if you are using the overage allowance). Excess emails are rejected, not queued.
- Probation cap reached: excess emails are held and released the next day.
- Rate limit reached (per user or maximum sending speed): individual messages are rejected in real time until you slow down.
You will see clear bounce or error messages in your activity log either way. If a rejection message is unfamiliar, our guide to email delivery errors covers the most common ones.
We also send proactive usage notifications, because nobody likes finding out about a cap after the fact. You will get an email at:
80%, 90%, 95%, and 100% of your monthly allowance, and again at 180%, 200%, 280%, and 300% if you are using the overage allowance.
How to Send More
When you outgrow a limit, the path forward is usually one of these:
- On free and hitting the hourly cap? Verify your sender domain. The 25/hour limit disappears automatically.
- Hitting the monthly cap regularly? Move to the next plan tier. Compare options on the pricing page.
- Need more than 200,000/hour? Message support with your target volume. We can lift the cap, often same day.
- Sending above 100K/month and serious about deliverability? Look at a dedicated IP and a structured warm-up. We have a full high volume sending guide and a warm-up playbook for exactly this.
- Above 3 million/month or need custom terms? Premier is built for that. Get in touch and we will scope it.
Frequently Asked Questions
Does the free plan ever expire?
No. Use it for as long as it fits.
Can I exceed my paid monthly allowance?
Yes. Every paid plan can send up to 3x its monthly limit, with overage billed per thousand at your plan’s rate.
What is the SMTP2GO daily sending limit?
On free, 200 emails per day. On paid plans, there is no hard daily cap (only the maximum sending speed of 200,000/hour and your monthly allowance), except during the probation period for new accounts, which is 1,000/day until review completes.
How do I increase my sending speed beyond 200,000 emails per hour?
Contact support with your target volume. The 200,000/hour figure is a default, not a ceiling.
Are there limits on recipients per message or attachment size?
Yes, and they are documented in our help center. For most senders, neither limit becomes relevant in normal use.
Do unsent emails carry over to the next month?
No. Allowances reset at the start of each billing cycle.
Send Confidently, Scale When You Are Ready
SMTP2GO has handled outgoing email for over 35,000 senders since 2006, ISO 27001 certification, and a support team that picks up the phone. Our limits exist to keep that track record intact, and almost every one of them is adjustable when your sending demands more.
Start free (1,000 emails/month, no credit card), compare paid plans, or talk to us if you need a custom setup.
About the author
Charlotte James
Charlotte specialises in email deliverability and inbox placement. Writing for SMTP2GO since 2014, she has explored topics such as authentication protocols, bounce handling, deliverability strategies and real-world customer success stories. Her work focuses on helping senders navigate the technical and policy changes - from evolving ISP requirements to authentication standards - that influence email performance.
thanks for this!