Zoho Mail limits and policies

To maintain system health, ensure optimal deliverability, and protect accounts from abuse, Zoho Mail enforces various limits on email sending, storage, and other features. Understanding these limits helps you use Zoho Mail effectively and avoid service interruptions.

Table of Contents

• Email sending & recipient limits
  • Email sending limits
  • Email receiving limits
• Email forwarding limits
• Email filter limits
• Domain, alias & user management
• Mailbox & storage limits
• Groups & collaboration
• Email & log retention
• Reports & eDiscovery
• Migration limits
• IMAP/POP & device limits
• API & Security policies
• Subscription & Grace periods
• Additional features & limits
• Enterprise & Custom solutions

Email sending & recipient limits

Sending limits operate on a 1-hour rolling basis rather than resetting at a specific daily cut-off time. This approach ensures consistent email deliverability standards and protects against potential misuse.

Emails included in limit calculations

Your sending quota encompasses all outbound email activity from your account, including:

• Direct emails composed and sent from your mailbox
• Correspondence sent through any alias addresses associated with your account
• Emails transmitted by others who have been granted delegate permissions to your mailbox
• Out-of-office replies and automated response messages triggered by your account settings

Email sending limits

What happens when you exceed sending limits?

If your users exceed an email sending limit, they'll receive error messages such as:

• "You have reached your email sending limit"
• "Daily sending quota exceeded"
• "Maximum recipients limit reached"

Account status during restriction period:

After reaching a sending limit, users cannot send new messages for up to 1 hour. However, during this period:

• Email receiving continues to function normally
• Account access remains fully available
• Other Zoho Mail features (reading, organizing, searching) work without interruption
• Limits automatically reset after the 1-hour restriction period

Best practices for email sending

To maximize your sending limits and maintain good deliverability:

• Send relevant content to engaged recipients
• Maintain clean mailing lists and remove inactive contacts
• Avoid spam complaints by following email marketing best practices
• Gradually increase sending volume rather than sudden bursts
• Monitor bounce rates and remove invalid email addresses
• Use Zoho Campaigns for your email marketing needs

Related resources:

• Zoho Mail usage policy
• For email marketing: Zoho Campaigns
• For transactional emails: Zeptomail

Email receiving limits

Zoho Mail implements receiving limits to maintain system efficiency and protect your account from potential abuse through excessive incoming message volume.

Incoming email limits

What counts as incoming mail

All messages delivered to your mailbox count toward receiving limits:

• Direct emails sent to your primary address
• Messages sent to your configured email aliases
• Emails forwarded from other accounts
• Automated notifications and system-generated messages
• Mailing list subscriptions
• Calendar invitations and meeting requests

What happens when receiving limits are exceeded?

If your account reaches the incoming message limit:

• Mail delivery suspended for approximately 24 hours
• New messages are rejected and bounced back to the senders
• Account access continues - you can read existing emails and send messages
• Limits automatically reset after the suspension period

Best practices to avoid incoming email blocking

Use groups for high-volume mail:

• Create organizational groups for departmental announcements
• Set up distribution lists for mailing list subscriptions
• Designate specific mailboxes for automated alerts and monitoring reports

Manage email aliases:

• Limit aliases per account to 30 or fewer when possible
• Review and remove unused or redundant aliases regularly

Avoid catch-all configurations:

• Catch-all addresses receive spam sent to non-existent addresses
• High spam volumes can rapidly trigger receiving limits
• Create specific aliases only for known, required addresses

Organize automated messages:

• Route system notifications to dedicated accounts
• Use filters to organize incoming automated messages into specific folders
• Configure systems to send summary reports rather than individual alerts

Related resources:

• Email filter configuration
• Setting up email groups

Email forwarding limits

Forwarding configuration

Manual forwarding allows you to forward incoming emails to external addresses automatically. Filter-based forwarding provides more flexibility without limit restrictions.

Email filter limits

Filters help automate email management by applying rules to incoming messages.

What happens when filter limits are exceeded?

If you exceed 30 filter creations per minute, additional creation attempts will be temporarily blocked until the rate limit window resets.

Best practices for filters

• Organize filters by priority, placing the most important rules first
• Test filters with sample emails before enabling
• Regularly review and remove unused filters
• Use specific conditions to avoid unintended matches

Domain, alias & user management

Email aliases allow you to receive mail at multiple addresses that all deliver to the same mailbox. This is useful for managing different roles or departments without creating separate accounts.

Mailbox & storage limits

Storage and folder limits

What happens when storage & folder limits are exceeded?

• Folder creation rate: creating more than 30 folders per minute triggers rate limiting. Wait for the rate limit window to reset.
• Mailbox storage full: when storage is full, you cannot receive new emails until space is freed by deleting messages.
• Import size exceeded: files larger than 500 MB cannot be imported and will be rejected with an error message.

Storage management tips

• Delete unnecessary emails and empty trash
• Use search to identify and remove large attachments
• Enable automatic deletion of emails older than a specified period
• Consider storage add-ons if approaching limits

Groups & collaboration

Organization group limits

Groups enable team collaboration and shared email management. The limit of 75% of licenses ensures sufficient resources for individual accounts while supporting collaboration.

Group management tips

• Create groups based on departments, projects, or functions
• Assign moderators to manage group membership and content
• Set clear naming conventions for easy identification
• Regularly review and remove inactive groups
• Use group aliases for easier addressing

Related resources:

Advanced Group settings

Email & log retention

Understanding retention periods helps with compliance and data management.

Retention policies ensure optimal system performance while maintaining necessary records for compliance and support purposes.

Reports & eDiscovery

Export limits and message trace retention

Message tracing helps administrators track email delivery and diagnose issues. While the server retains 6 months of data, the user interface displays the most recent month for optimal performance.

Using reports effectively

• Generate reports regularly for compliance and monitoring
• Download exports in Admin Reports promptly before the 30-day expiration
• Download exports in eDiscovery before the 90-day expiration
• Use message trace to troubleshoot delivery issues
• Archive important reports for long-term record keeping

Migration limits

For organizations migrating to Zoho Mail from other email providers:

Migration best practices

• Plan migrations during off-peak hours to minimize user impact
• Migrate users in batches rather than all at once
• Test migration with a small group before full rollout
• Communicate migration schedules clearly to users
• Keep backup of data before starting migration
• Verify data integrity after migration completes

Related resources:

• Migration to Zoho Mail
• Troubleshooting Migration

IMAP/POP & device limits

Third-party email clients can access Zoho Mail via IMAP or POP protocols, subject to connection and bandwidth limits.

What happens when device limits are exceeded?

• Connection limits: New connections are blocked until existing connections are closed
• Fetch limits: Additional fetch requests are blocked until the limit resets (24 hours for daily limits, 15 minutes for rate limits).

Best practices for IMAP/POP usage

• Use native Zoho Mail apps when possible for better resource management
• Close inactive connections in email clients
• Monitor daily fetch usage if using POP
• Limit the number of devices configured with IMAP/POP
• Consider using webmail for occasional access instead of configuring additional devices.

Related resources:

• Configure IMAP/POP in Zoho Mail
• Troubleshooting IMAP/POP connection issues

API & Security policies

For developers and organizations using Zoho Mail APIs, the following limits apply:

What happens when API limits are exceeded?

If you exceed 30 API requests per minute, subsequent requests will be blocked for a locking period. The duration is not publicly disclosed for security reasons.

API usage best practices

• Implement exponential back-off for retries
• Cache responses when possible to reduce API calls
• Monitor your API usage to stay within limits
• Distribute API calls evenly over time rather than bursts
• Use webhooks for event-driven notifications instead of polling

Related resources:

• API Guide Index
• OAuth 2.0 User Guide

Subscription & Grace periods

Payment and storage policies

After payment failure, your organization has 15 days to update payment information before service restrictions apply. However, domain renewals must be completed on time to avoid loss of domain access.

Refer to our help page for more information on account blocking due to subscription expiration or cancellation.

Managing your subscription

• Enable automatic payment renewal to avoid service interruptions
• Monitor payment method expiration dates
• Set up billing alerts for upcoming renewals
• Keep backup payment methods on file
• Respond promptly to payment failure notifications

Additional features & limits

General constraints

Managing rules and contacts effectively

Email rules:

• Prioritize rules by importance
• Combine similar rules to reduce total count
• Regularly audit and remove obsolete rules
• Test rules before enabling to avoid unintended actions

Contacts management:

• Regularly clean up duplicate contacts
• Use tags and categories for organization
• Export contacts periodically for backup
• Remove outdated or invalid contact information
• Consider integration with Zoho CRM for larger contact databases

Related resources:

• Incoming Rules
• Contacts

Enterprise & Custom solutions

The limits documented here apply to standard Zoho Mail accounts. Enterprise customers with high-volume requirements or specific needs may have customized limits.

Options for higher limits

If your organization's needs exceed standard limits:

1. Upgrade to paid plan - Free accounts have lower limits than paid subscriptions
2. Build sender reputation - Consistent, legitimate sending patterns can increase dynamic limits
3. Purchase add-ons - Storage and other features can be expanded with add-ons
4. Contact enterprise sales - Discuss custom configurations for high-volume requirements
5. Use specialized tools - Consider Zoho Campaigns for marketing, Zeptomail for transactional emails
6. Request custom limits - Work with our support team to adjust specific limits based on legitimate business needs

Recommended best practices

To ensure optimal performance and avoid hitting limits:

For Administrators

• Monitor user sending patterns and storage usage
• Set up alerts for users approaching limits
• Educate users on email best practices
• Implement email retention policies
• Regularly review and optimize email rules
• Plan for growth when approaching organizational limits

For Users

• Send targeted, relevant emails to engaged recipients
• Clean up mailbox regularly to manage storage
• Use filters and rules efficiently
• Close unused IMAP/POP connections
• Report spam and phishing attempts promptly
• Keep alternative email methods for critical communications during restrictions

For developers

• Implement proper error handling for API rate limits
• Use exponential back-off strategies for retries
• Cache data when possible to reduce API calls
• Monitor API usage and implement alerts
• Follow API documentation and best practices
• Test thoroughly before production deployment

Reporting issues

If you believe you're experiencing issues related to these limits:

1. Check your current usage against the limits
2. Review recent sending patterns for unusual activity
3. Contact your administrator if in an organization
4. Reach out to our support team at support@zohomail.com with specific details
5. Provide relevant error messages and timestamps