Mailbox size and message sending limits in iCloud
Learn about iCloud Mail account mailbox size and message sending limits. Since iCloud Mail is designed for personal use, there are a few limits when you send a message.
Limits on sending messages
There are several safeguards in place to make sure that only iCloud members can send messages using iCloud. One of these safeguards includes reasonable limits on:
The total number of messages you can send each day (1000 messages)
The number of recipients you can message each day (1000 recipients)
The maximum number of recipients per message (500 recipients)
The size of incoming and outgoing messages (20MB, up to 5GB with Mail Drop turned on)
iCloud Mail service is designed primarily for personal use. Sending unsolicited bulk email messages through iCloud email servers is prohibited. To review the iCloud membership agreement and acceptable use policy, please see the iCloud terms and conditions.
When you exceed message sending limits, you might see the following alert messages depending on how you view iCloud Mail:
On your iPhone, iPad, or iPod touch: A copy has been placed in your Outbox. Sending the message failed because you exceeded your sending limit.
On your Mac: Cannot send message using the server iCloud.
On iCloud webmail: Cannot send message. You have exceeded the total number of messages you can send each day (or you have exceeded the total number of receipients you can message each day). Or, Recipient limit exceeded. This message cannot be sent because it has too many recipients.
If you continue to exceed message sending limits, follow these steps:
Check your Mail Outbox to see if it contains unsent messages. Resend or delete the unsent messages.
Check for any network monitoring software that might be using your iCloud Mail account to automatically send messages (like firewalls or internet security software that sends alerts about security issues).
If you send messages to groups, make sure that all email addresses in the group are valid (for example, make sure that all email addresses are spelled correctly).
If you run out of iCloud storage
When you sign up for iCloud, you automatically get 5GB of free storage. You can use that storage for backups, Mail, iCloud Photos, iCloud Drive, and more. If you run out of iCloud storage, you won't be able to send or receive emails with your iCloud Mail address. If you need more space in iCloud, you can make more space or upgrade to iCloud+ any time.