Sending limits
How many emails you can send before you hit the cap
You put together your newsletter, hit “Send” and, halfway through the list, a warning pops up: you’ve reached your sending limit. The remaining emails are left hanging. It’s one of the most common surprises for anyone who starts sending campaigns from their own mailbox. And there’s a simple explanation: every email provider sets a cap.
What are sending limits?
Sending limits are the maximum number of emails or recipients you can send in a given period: per hour, per day or per month. They are set by your mailbox provider, the server that sends the messages or the email marketing platform you use.
Their purpose is to curb spam and protect the infrastructure. If an account suddenly fires off thousands of emails, it’s natural to be suspicious. Maybe someone has hacked it or is using it to send unsolicited advertising.
It’s worth telling them apart from two related concepts. Email throttling is the technique of pacing your sending rate so you don’t overload the receiving servers. And bulk sender requirements are the rules Gmail, Yahoo and Outlook impose on anyone who sends high volumes. Limits set how much; those rules set how.
Send to your whole list without hitting a daily limit
With Mailrelay’s free account you get up to 80,000 emails a month and 20,000 contacts, with no daily cap and no credit card.
Types of sending limits
There isn’t just one sending limit. Depending on where you send from, one or another will affect you:
- Mailbox: Gmail, Outlook or Yahoo limit how many recipients you can reach per day from a personal or business account.
- SMTP server: many hosting providers and mail servers limit the messages per hour for each account.
- Email marketing platform: your plan includes a monthly volume of emails and a maximum number of contacts.
- Receiving server: Gmail, Outlook and the other providers accept incoming mail at a rate based on your reputation. If you exceed it, they return temporary errors and your emails wait in a queue.
Gmail and Outlook sending limits
These are the official sending limits of the most widely used providers. Keep them in mind if you still send your campaigns from your own mailbox.
A personal Gmail account trips the limit if you send more than 500 emails in a day or put more than 500 recipients in a single message. A warning appears saying you’ve reached your sending limit, and you won’t be able to send any more for a period of 1 to 24 hours.
With Google Workspace there’s more headroom: 2,000 messages per day per user, or 500 if the account is in its trial period. Each message can have up to 2,000 recipients, of which a maximum of 500 can be external. If you exceed the cap, the user may be unable to send for up to 24 hours.
On Outlook.com, Microsoft 365 subscribers can reach up to 5,000 recipients per day, with a maximum of 500 per message. Of those, only 1,000 can be people you’ve never written to before. Free and newly created accounts have lower limits, which rise as the account builds trust.
What if your list has 3,000 contacts? With Gmail it would take you six days to reach them all. That’s why these mailboxes are fine for everyday email, but not for email marketing. On our blog you’ll find a comparison of bulk sending with Gmail vs. Mailrelay.
Bulk senders: the 5,000-email threshold
There’s another key number. Since February 1, 2024, Gmail considers anyone who sends 5,000 or more emails in a day to personal Gmail accounts a bulk sender. Yahoo applies similar rules, and Microsoft followed suit on May 5, 2025 for Outlook.com, Hotmail and Live.
Going over that volume isn’t prohibited. But it means you have to meet more requirements. You need to authenticate your domain with SPF, DKIM and DMARC and offer one-click unsubscribe. In addition, your spam rate must stay below 0.3%. Google recommends not going above 0.1%.
And the consequences are already real. Since November 2025, Gmail rejects emails that don’t comply. Outlook, for its part, bounces them with error 550 5.7.515. You’ll find all the details in our article on what Outlook, Gmail and Yahoo require to keep your emails out of spam.
What happens if you exceed a sending limit
It depends on who sets the sending limit. If it’s your mailbox, the account is blocked from sending for a few hours. If it’s your platform, the campaign is paused until you upgrade your plan or a new period begins.
When the limit is set by the receiving server, messages come back as temporary bounces, or soft bounces, and are retried later. That’s why a campaign sometimes takes hours to be fully delivered. We explain it in detail in why some emails get stuck in the queue.
The underlying problem is sender reputation. Hitting sending limits over and over, or suddenly sending far more than usual, is a red flag for filters. And rebuilding that reputation takes weeks.
How to send more without problems
Before you run into a sending limit, work out how much you need. Multiply your contacts by the number of sends you’ll do each month. A list of 8,000 people with a weekly newsletter and one promotion a month adds up to about 40,000 emails. With that figure you’ll know whether your tool and your plan fall short.
Next, increase your volume gradually. If you’re going from 2,000 to 50,000 emails, do it over several weeks. This is known as IP warming, and providers appreciate it.
Look after your list. Addresses that no longer exist generate bounces and damage your reputation. Good email list hygiene and double opt-in reduce those errors.
Authenticate your domain even if you don’t reach 5,000 emails a day. It’s the norm today and it improves deliverability for any sender.
And don’t include your entire database in every campaign. Segmenting reduces volume, raises open rates and lowers spam complaints.
Sending limits in Mailrelay
Mailrelay has no daily limit. The free account includes up to 80,000 emails a month and 20,000 contacts, and you can spread them out however you like: all in one campaign or across several sends throughout the month.
During the first five days, our system analyzes new free accounts to optimize delivery speed. If you move to a paid plan, your sending speed increases within minutes.
Keep two details in mind. Each email over 100 KB counts as one extra send for every 100 KB block. And if you use up your plan’s volume or contacts, your campaigns are paused until renewal, unless you upgrade your plan or buy a sending package.
We also help you with what lies behind the limits. You get domain authentication, real-time bounce and complaint reports, and expert technical support, on the free account too.
Stop worrying about your mailbox’s caps
80,000 free emails a month, high deliverability and a support team that helps you set up your domain from day one.
Frequently asked questions about sending limits
How many emails can I send per day with Gmail? With a personal account, 500 a day. With Google Workspace, 2,000 per user, or 500 during the trial period.
And with Outlook? Microsoft 365 subscribers can send to 5,000 recipients a day from Outlook.com, with a maximum of 500 per message. Free and new accounts have lower limits.
What is a bulk sender? Anyone who sends 5,000 or more emails in a day to Gmail or Outlook accounts. They must authenticate their domain, offer one-click unsubscribe and keep a low spam rate.
Does Mailrelay have a daily sending limit? No. The free plan includes 80,000 emails a month and 20,000 contacts, with no daily cap.
What happens if I exceed my plan’s limit in Mailrelay? Your campaigns are paused until renewal. You can upgrade your plan or buy a sending package to keep sending.
In summary
Sending limits exist everywhere: in your mailbox, on your server, on your platform and at the providers that receive your emails. Knowing them saves you from getting blocked mid-campaign. If your list grows, keep your personal mailbox for everyday use, authenticate your domain, increase your volume little by little and use a tool built for sending to thousands of contacts.