Email Sending Limits by Provider: 2025 Complete Guide

📅 Last Updated: December 8, 2025

Understanding email sending limits is critical for anyone conducting cold email outreach, running email marketing campaigns, or managing business communications. Every major email service provider enforces specific restrictions on how many emails you can send per day, per hour, and to how many recipients. These limitations help prevent spam, maintain server performance, and protect sender reputations.

In this comprehensive guide, we’ll break down the email sending limits for Gmail, Outlook, Yahoo, and dozens of other providers, explain why these restrictions exist, and share proven strategies to maximize your email deliverability while staying within compliance.

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📊 See the full limits comparison table (all providers)
📧 Gmail and Google Workspace limits (most requested)
💼 What happens when you exceed limits
✅ Best practices to stay compliant
🚀 Solutions for high-volume senders

Want the complete playbook? Keep reading—this guide covers everything from understanding why limits exist to advanced strategies for scaling your email operations.

What Are Email Sending Limits?

Email sending limits are restrictions imposed by email service providers (ESPs) on the number of messages users can send within specific timeframes. These limits typically include:

Daily sending limits – The maximum number of emails you can send in a 24-hour rolling period
Hourly sending limits – Caps on emails sent per hour to prevent spam-like sending patterns
Per-message recipient limits – Maximum number of recipients allowed in a single email
Rate limits – Restrictions on how quickly emails can be sent (emails per minute)
Attachment size limits – Maximum file size for email attachments
SMTP relay limits – Separate restrictions when sending via SMTP protocols

These limits vary significantly based on your account type (free vs. paid), account age, sending history, and the specific email provider you’re using.

Why Email Service Providers Enforce Sending Limits

Spam Prevention and Network Health

Email providers implement sending limits primarily to combat spam and maintain the health of their email ecosystems. Without these restrictions, malicious actors could flood inboxes with unwanted messages, degrading the experience for all users. According to industry research, over 361 billion emails are sent daily worldwide, with a significant portion being spam attempts.

Server Performance Management

Email servers aren’t designed to handle unlimited data transfer. Sending limits prevent server overload and ensure consistent performance for all users. When someone attempts to send massive volumes of emails or large attachments, it can strain server resources and impact delivery times for everyone on the network.

Account Security Protection

Sudden spikes in sending volume often indicate a compromised account. By enforcing daily and hourly limits, providers can detect and stop unauthorized access before significant damage occurs. If your account starts sending hundreds of emails when you typically send a dozen, it triggers security alerts.

Email Ecosystem Integrity

These restrictions help maintain the overall deliverability and reputation of the provider’s email infrastructure. When one user violates sending best practices, it can negatively impact the IP reputation for all users sharing that infrastructure, particularly with free email services.

Email Service Provider	Daily Sending Limit	Hourly Sending Limit	Recipient Limit Per Email	Attachment Size Limit	Additional Notes
Free Gmail	500 (browser) / 100 (SMTP)	–	500 total recipients	25MB	Account suspended if exceeded
Google Workspace	2,000 messages / 500 (trial)	–	3,000 unique / 2,000 external	25MB	Rolling 24-hour period
Office 365	10,000 recipients	30 messages/minute	500 per message	150MB (Outlook)	Academic: 2,000/day (faculty), 500/day (students)
Outlook.com	5,000 emails	100 estimated	500	25MB	Limits vary by account history
GoDaddy	500 emails	300 messages/hour / 200 messages/minute	–	30MB	Can add SMTP relays
Rackspace	10,000 recipients	–	–	50MB	Focus on message quality
BlueHost	Not specified	150 emails/hour	–	50MB	Can request hourly increase
DreamHost	–	100 recipients/hour	–	40MB	Different limits for bulk sends
Yahoo! Mail	500 emails	100 emails/hour (estimated)	100	25MB	Each recipient counts separately
Yandex.mail	500 emails	–	50	1GB	Each recipient counted separately
HostGator	12,000 emails	500 emails/hour	–	20MB	Mailing lists 900+ only during off-peak
iCloud Mail	1,000 emails	–	500	20MB	–
ProtonMail Free	150 emails	50 emails/hour	–	25MB	Increases with account age
Zoho Mail	250/day (Standard), 500/day (Professional), 1,000/day (Enterprise), 2,000/day (Ultimate)	–	Varies by plan	Varies by plan	Can upgrade to 2,500/day for additional cost
one.com	No official limits	25 emails per 5 minutes	–	70MB total	Use cautiously
OVH	500/day (Perso/Pro), 1,200/day (Business), 2,000/day (Premium)	Max 100/hour	–	Plan-dependent	SMTP and PHP mail options
PHPNet	Unlimited queued	600/hour	–	–	–
Rochen	1,000/day	100/10 minutes	–	–	–
ServerMX.com	15-3,000/day (tier-based)	10-1,000/hour (tier-based)	–	–	Depends on account size
Siteground	–	800/hour	80	50MB	–
AOL Mail	500 emails	–	100	25MB	–
Tutanota	–	100/hour	–	20MB	–

Gmail and Google Workspace Sending Limits

Free Gmail Account Limits

Free Gmail accounts face the most restrictive sending limits, designed for personal use rather than business communications:

Daily limit: 500 emails when sending through the Gmail web interface
SMTP daily limit: Only 100 emails when using SMTP (Simple Mail Transfer Protocol) for automated sending
Recipients per message: Up to 500 total recipients
Rate limit: Approximately 20 emails per hour recommended to avoid spam filters
Attachment size: 25MB maximum (larger files automatically convert to Google Drive links)

The limit operates on a rolling 24-hour window, not a calendar day. If you send 400 emails at 8 PM on Monday, you won’t be able to send another 500 until after 8 PM on Tuesday.

Google Workspace Limits

Google Workspace (formerly G Suite) provides significantly higher limits for business users:

Daily limit: 2,000 emails per user per day
Trial accounts: Limited to 500 emails during the trial period
Unique recipients: 3,000 unique recipients per day
External recipients: Maximum 2,000 recipients outside your domain
Internal recipients: Unlimited within your organization’s domain
Attachment size: 25MB per email
API and SMTP: Same 2,000 email limit applies

For organizations sending cold email campaigns, Google Workspace is essential. The free Gmail limit of 100-500 emails makes it inadequate for any serious outreach efforts.

Gmail SMTP Sending Limits

When using Gmail’s SMTP relay service for automated sending, different restrictions apply:

Per-user limit: 2,000 recipients per day for Workspace users
Per-account limit: Approximately 130 times the number of users in your account
10-minute window: Approximately 9 times the number of users
New accounts: Limited to 100 recipients per day for the first month

SMTP relay is particularly useful for applications, multifunction devices, or line-of-business systems that need to send email without a traditional email client.

Microsoft Outlook and Office 365 Limits

Microsoft takes a more generous approach with Office 365 and Outlook.com accounts:

Office 365 Business Accounts:

Daily limit: 10,000 recipients per day
Per-message limit: 500 recipients per individual email
Rate limit: 30 messages per minute
Attachment size: 150MB via Outlook desktop client, 34MB via Outlook Web Access

Academic Office 365 Accounts: As of May 2025, stricter limits apply to educational accounts:

Faculty/Staff: 2,000 recipients per day
Students/Affiliates: 500 recipients per day

Outlook.com (Free):

Daily limit: 300 recipients in a 24-hour period, with ability to increase to 5,000 based on account history
Per-message limit: 500 recipients
Rate limit: Estimated 100 emails per hour
Attachment size: 25MB

Mail Merge Workaround: When using Office 365’s mail merge feature, each recipient counts as a separate message rather than multiple recipients on a single message, potentially helping you work within the 500 per-message restriction while still respecting the 10,000 daily limit.

Yahoo Mail Sending Restrictions

Yahoo Mail implements relatively conservative sending limits:

Daily limit: 500 emails per day
Hourly limit: 100 emails or recipients per hour
Recipients per email: 100 maximum
Attachment size: 10MB for free accounts, 20MB for Yahoo Mail Plus subscribers
Important note: Each recipient counts separately toward your limit, meaning one email to 50 recipients counts as 50 emails

Yahoo’s limits reset after the time period expires, but the exact reset mechanism isn’t publicly documented. Conservative sending practices are recommended to avoid account restrictions.

Web Hosting Email Limits

Web hosting providers typically offer email services with varying limits based on your hosting plan:

GoDaddy:

Basic plans: 250 emails/day
Professional email: 500 emails/day
Can add SMTP relays to increase capacity
300 emails/hour or 200 emails/minute
30MB attachment limit

BlueHost:

150 emails per hour (can request increases)
50MB attachment size
Speed limit errors indicate you’ve exceeded hourly caps

HostGator:

12,000 emails per day
500 emails per hour
Mailing lists over 900 addresses only during off-peak hours (12 AM – 8 AM CST)
20MB attachment limit

SiteGround:

800 emails per hour
80 recipients per email
50MB attachment size

DreamHost:

100 recipients per hour
Different limits apply when sending multiple messages versus single messages with multiple recipients
40MB attachment limit

Web hosting email is generally not recommended for serious email marketing campaigns or cold outreach due to lower deliverability compared to dedicated email services.

What Happens When You Exceed Email Limits

Exceeding your email provider’s sending limits can have serious consequences:

Immediate Effects:

Temporary suspension: Most providers block sending for 24 hours after hitting limits
Bounced emails: Messages sent after reaching your limit will fail to deliver
Error messages: You’ll receive warnings like “You have reached a limit for sending mail” or “You exceeded the maximum recipients”
Account lockout: Some providers may lock your entire account temporarily

Long-term Consequences:

Damaged sender reputation: Your email domain reputation can suffer, causing future emails to land in spam folders
IP blacklisting: Aggressive sending can get your IP address added to email blacklists
Permanent restrictions: Accounts that repeatedly violate limits may face permanent sending restrictions
Account termination: Severe or repeated violations can result in account closure

The financial impact can be significant. With email marketing generating an average ROI of $36-40 for every dollar spent, account suspensions directly jeopardize potential revenue and disrupt your sales pipeline.

Best Practices for Staying Within Limits

Monitor Sending Frequency and Volume

Track your daily and hourly email volume to ensure you stay well below your limits. Most email providers offer analytics showing how many emails you’ve sent. Consider implementing a tracking spreadsheet or using email software that displays sending statistics in real-time.

Pro tip: Aim for 70-80% of your daily limit rather than pushing to 100%. This provides a safety buffer for unexpected needs.

Warm Up Email Accounts Gradually

New email accounts shouldn’t immediately send hundreds of emails. Providers view sudden high-volume sending from new accounts as suspicious behavior. Instead:

Week 1: Send 10-20 emails per day
Week 2: Increase to 30-50 emails per day
Week 3: Gradually increase to 75-100 emails per day
Week 4+: Continue increasing by 25-50 emails per day

This gradual ramp-up establishes your sending pattern as legitimate and helps build a positive sender reputation.

Segment Your Email Lists

Rather than sending one massive campaign, divide your email list into smaller segments and schedule sends across multiple days. This approach offers several benefits:

Stays within daily limits
Allows for more personalized messaging
Enables A/B testing different approaches
Reduces the risk of being flagged as spam

For example, instead of sending to 5,000 contacts in one day with Google Workspace, segment into three groups of 1,666 and send over three days.

Use Email Verification Tools

Bounced emails damage your sender reputation and waste your sending limits. Before launching campaigns:

Verify email addresses are valid and deliverable
Remove inactive or abandoned email addresses
Check for typos and formatting errors
Regularly clean your email list to remove hard bounces

Email verification services can check your list against databases of known invalid addresses, role-based emails, and spam traps.

Maintain Strong Sender Reputation

Your sender reputation directly impacts deliverability. To maintain a positive reputation:

Keep bounce rates below 2%
Maintain spam complaint rates under 0.1%
Ensure strong engagement rates (opens, clicks, replies)
Never purchase email lists
Always include a clear unsubscribe option
Honor unsubscribe requests immediately

Implement Email Authentication

Proper email authentication significantly improves deliverability and prevents your emails from being marked as spam:

SPF (Sender Policy Framework): Specifies which servers can send email from your domain
DKIM (DomainKeys Identified Mail): Adds a digital signature to verify email authenticity
DMARC (Domain-based Message Authentication): Provides instructions on handling emails that fail SPF or DKIM checks

These authentication protocols help test email deliverability and are increasingly required by major email providers.

Plan Campaign Timing Strategically

Be aware of cumulative effects when multiple campaigns or follow-up sequences overlap:

Track all automated sequences and their daily volume
Schedule campaigns to avoid simultaneous large sends
Account for follow-ups when calculating daily totals
Use email automation tools that respect sending limits

If you have three follow-up sequences each sending 200 emails per day, that’s 600 emails before you’ve even sent any new campaigns.

Advanced Solutions for High-Volume Email Sending

When your email needs exceed standard provider limits, you have several options. You can build your own infrastructure with SMTP relays and multiple accounts, or partner with a managed outreach service that handles the technical complexity for you.

SMTP Relay Services

SMTP relay services route your outgoing mail through specialized servers designed for high-volume sending. They offer:

Higher sending limits than standard email accounts
Better deliverability rates
Advanced analytics and tracking
Dedicated IP addresses
Professional support

Popular SMTP Relay Options:

SendGrid: Up to 100 emails/day free, paid plans for high volume
Mailgun: 5,000 emails/month free, then pay per email
Amazon SES: Very low cost, high volume capabilities
Mandrill: 12,000 emails/month free through MailChimp
SMTP2Go: 1,000 emails/month free

When using SMTP relay with Google Workspace, note that relay limits differ from standard Gmail limits – typically 10,000 messages per day per user with paid accounts.

Multiple Email Accounts Strategy

For serious cold email outreach, many organizations use multiple email accounts to distribute sending volume:

Create 5-10 email accounts per sender
Rotate sending across accounts
Keep each account under 50 emails per day
Use domain rotation to protect primary domain reputation

This “inbox rotation” strategy protects your primary domain and allows for significantly higher total volume. If one account gets flagged, it doesn’t impact your entire operation.

Managing multiple accounts yourself can be complex. If you’d rather focus on your core business, our managed email outreach service handles the entire infrastructure—from setting up and warming multiple accounts to rotating sends and monitoring deliverability across your entire email operation.

Dedicated Email Service Providers

For organizations regularly sending thousands of emails, dedicated email service providers (ESPs) are the most reliable solution:

Mailchimp: Designed for marketing campaigns
Constant Contact: User-friendly interface for businesses
ActiveCampaign: Advanced automation capabilities
Sendinblue: Affordable pricing with SMS integration
HubSpot: Comprehensive marketing platform

These platforms are specifically built for bulk sending and include features like:

List management and segmentation
A/B testing capabilities
Detailed analytics and reporting
Compliance tools for regulations like CAN-SPAM and GDPR
Template builders and personalization

FAQs About Email Sending Limits

How many emails can I send with Gmail per day?

Free Gmail accounts can send 500 emails per day through the web interface or 100 per day via SMTP. Google Workspace accounts can send 2,000 emails per day.

Do email limits reset at midnight?

No. Most providers use a rolling 24-hour period, not a calendar day. Your limit resets 24 hours after you sent your first email of the period.

Can I increase my email sending limits?

With paid accounts like Google Workspace or Office 365, limits are higher than free accounts. Some web hosts allow limit increases upon request. For volumes exceeding standard limits, SMTP relay services or dedicated ESPs are recommended.

What counts as “one email” toward my limit?

This varies by provider. Some count each unique recipient as one email, while others count each message sent. Sending one email to 10 recipients might count as one email or 10 emails depending on the provider.

How long does an email suspension last?

Most temporary suspensions last 24 hours. Repeated violations can lead to longer suspensions or permanent account restrictions.

Are there limits on email size?

Yes. Most providers limit attachments to 20-25MB. Some services like Gmail automatically convert larger files to Google Drive links. Total message size (including headers, body, and attachments) typically cannot exceed 50MB.

Can I send unlimited emails with my own SMTP server?

While you control the technical limits, you must still follow best practices for sender reputation, comply with anti-spam laws, and maintain good deliverability. Unlimited sending without proper infrastructure often results in blacklisting.

Key Takeaways

Understanding and respecting email sending limits is fundamental to successful email communication, whether for personal correspondence, business outreach, or marketing campaigns. Key points to remember:

Know your limits: Every email provider has specific daily, hourly, and per-message restrictions
Choose the right account type: Free accounts are inadequate for business email campaigns
Warm up new accounts: Gradually increase sending volume to establish legitimacy
Monitor your metrics: Track bounce rates, spam complaints, and engagement to maintain good standing
Implement authentication: SPF, DKIM, and DMARC are essential for deliverability
Plan strategically: Account for all automated sequences and overlapping campaigns
Scale appropriately: Use SMTP relays, multiple accounts, or ESPs for high-volume needs
Consider managed solutions: If managing limits, accounts, and deliverability feels overwhelming, Done-For-You outreach services handle the technical details while you focus on closing deals

By following these guidelines and staying within your provider’s limits, you’ll maintain strong email deliverability, protect your domain reputation, and ensure your messages consistently reach recipients’ inboxes rather than spam folders.

For organizations conducting regular cold outreach or email marketing, investing in proper infrastructure—whether that’s upgrading to business email accounts, implementing SMTP relay services, or using dedicated email platforms—is essential for sustainable growth.

Ready to Scale Your Email Outreach?

Managing email sending limits, warming accounts, and maintaining deliverability takes time and expertise. Choose the approach that fits your needs:

DIY with Growth List – Get targeted lead lists and manage outreach yourself
Done-For-You Service – We handle everything: list building, account setup, email warming, sending rotation, and deliverability monitoring
Custom Lead Lists – Tailored prospect lists built to your exact specifications

Whether you prefer hands-on control or a fully managed solution, Growth List helps you reach the right prospects while maintaining best practices for email deliverability.

Email Sending Limits of Various Email Service Providers in 2025