Gmail Service Restrictions

Overview

Gmail has several limits when sending emails, if you exceed these you may see an error message such as:

• You have reached a limit for sending email
• You reached a Gmail sending limit
• You exceeded the maximum recipients

Google has implemented limits on the amount of email one user can send in order to maintain the health of their systems as well as keeping your account safe. The limits restrict the number of messages sent per day and the number of recipients per message. After reaching one of these limits, a user can't send new messages for up to 24 hours after the limit was exceeded; however, they can still access their account and receive incoming email.

These limits may change without notice by Google to protect their infrastructure. Limits per day are applied over a rolling 24-hour period rather than a set time of day.

In this article:

• Email Sending Limits
  • How long does a suspension last
  • Sending mail from another address
  • Recommendations for sending bulk email
• Email Receiving Limits
  • How long does a suspension last
  • Request limits
  • Bandwith limits
• Effects
• Sync Limits

Email Sending Limits

The following sending limits apply:

* Applies to both internal and external recipients

How long does a suspension last?

If an account reaches a sending limit, the restriction on sending new mail typically lasts for about 24 hours. After this period, sending limits are automatically reset and the user can resume sending mail.

Accounts that are detected as sending spam may be permanently restricted from sending mail.

Sending mail from another address

• In mail delegation, the sending limits of the delegator are applied to messages sent.
• When sending mail from a different address, the primary account's message limits are applied.
• Messages sent via Gmail's vacation responder (for example: Out of Office automatic replies and messages sent via forwarding rules) are counted toward the sending limits of the primary account.

Recommendations for sending bulk email

To send a large amount of mail such as for a marketing campaign, consider one of the following alternaties:

• Stagger mass communications over the course of several days. For example, send messages to one group of recipients, wait 24 hours, then send to another group. Repeat until all groups have been sent.
• Contact the IT Service Center and request the creation of a Mailman mailing list. Mail sent to the Mailman mailing list will be counted as a single recipient (i.e. the mailing list address) and the Mailman list will handle transmitting the mail to all individuals subscribed to the mailing list.

Email Receiving Limits

Google has implemented limits on the amount of email an individual can receive per minute, hour, and day in order to help them maintain their systems. Setting up the account to receive frequent automated messages, such as log files, increases the likelihood of reaching the limits.

If an account reaches the limite, an individual cannot receive any new email and may experience general account degradation, such as slow searching. All incoming messages are bounced or deferred back to the sender.

The following table shows limits for different time periods. These limits apply only for Google Apps for Work or Education editions. The value of these limits may change without notice in order for Google to protect their infrastructure.

How long does a suspension last?

If an account reaches a receiving limit, the restriction on receiving new mail typically lasts for about 24 hours. After this period, receiving limits are automatically reset and the individual can resume receiving mail. After an account is reset, a individual cannot recover any messages sent to the account during the restricted period.

Request Limits

Google has implemented restrictions on the number of server requests a Google Apps account can make at one time. Reaching the limit triggers a safeguard, which temporarily suspends the account.

Causes

• Using an outdated version of your mail client, or configuring the client to check for mail too often
• Sending files through file-sharing or file-storage software.
• Using third party software or services that automatically sign in to your Google acount.
• Changing your browser configurations and adding on extensions.
• Synchronizing your Google account or signing in with multiple computers, clients, and/or mobile devices.

When trying to access a suspended account, the individual receives an error message on the sign in page. The suspension typically lasts for one hour, but can last as long as 24 hours. The individual can sign in and access the account after this suspension period is over, at which time requests limits are automatically reset.

Recommendations

• Keep your mail client current and configure it to check for new messages less frequently; once every 15 minutes is recommended. Make sure you are using the latest version of your mail client.
• Share large files, such as spreadsheets, photos, and videos, using SharePoint Online, OneDrive for Business, or Google Drive.
• Uninstall third party software and revoke access from services that automatically sign in to your Google account.
• Clear your browser's cache and cookies regularly, and only use necessary and well documented extensions. Make sure you are using the latest version of your browser and extensions.

Bandwidth Limits

Google has implemented bandwidth restrictions on Google Apps accounts in order for them to help maintain their systems. Certain activities that transfer large amounts of data in a short period of time, like synchronizing a Gmail account to a mobile phone or mail client, can cause an account to reach the bandwidth limit.

See Sync limits below for recommendation specific to synchronization. Reaching the limit triggers a safeguard that temporarily disables IMAP upload for the account.

The following limits apply for Google Apps for Work or Education editoins. These limits may be changed without notice in order for Google to protect their infrastructure.

Web Client Bandwith Limits

POP and IMAP Bandwidth Limits

Effects

When trying to access a suspended account, you receive an error message on the sign in page. The suspension typically lasts for one hour but can last for as long as 24 hours. An individual can access and use the account again after the end of this suspension period, at which time the bandwidth limit is automatically reset.

Recommendations

• Reduce email label counts: Reducing the total number of labels in Gmail and the number of labels applied to each email lowers the number of folders and emails your Google account needs to transfer to your email client. Google recommend using no more than 500 labels.
• Use other resources to transfer and share files: Try an alternative to email when sharing many large files at the same time. Use other resources such as Department File shares, SharePoint Online, OneDrive for Business, and Google Drive to reduce the risk of your email account using excessive bandwidth.
• IMAP bandwidth limits: These items apply to any application that usesIMAP to synchronize email with Gmail, including common email clietns. Other sync methods count against the sync bandwidth limits.
  • Manage your IMAP clients: Having multiple clients means every message gets downloaded multiple times, proportionally increasing bandwidth consumption. Remove or disable unused IMAP clients, quit IMAP clients when not in use, and make sure all clients are configured according to Google's recommended IMAP client settings.
  • Check for unknown/unwanted IMAP clients: In some cases an individual may have setup an IMAP client and stopped using it without disabling it, or wasn't aware that a service or tool uses IMAP to access Google Apps. Individuals can navigate to their Google accounts authorizations page and revoke any unwanted items under Connected Sites, Apps, and Services and Application-specific passwords (if applicable). Individual's could also change their UA account password to make sure any IMAP clients set up using those passwords can no longer access the account anymore.
  • Check your IMAP sync settings: Synchronize few labels using the Show in IMAP checkboxes in the Labels tab of your Gmail settings. Google recommends synchronizing no more than 200 labels. Additionallly, you can synchronize fewer messages in each label by changing the Folder Size Limits value in the Forwarding and POP/IMAP tab of your Gmail settings.

Sync Limits

Google has implemented limits in the amount of bandwidth available for account synchronization just as it does for bandwidth in general. Exceeding these limits via sync can result in a temporarily suspended account.

Reaching the bandwidth limit for sync may be caused by any of these clients:

• Android Gmail app
• Google Sync clients (using the Microsoft Exchange ActiveSync protocol)
• G Suite Sync for Microsoft Outlook (GSSMO) clients
• Gmail Offline app for Google Chrome

Note that the actions of clients and services using IMAP, such as Mozilla Thunderbird, and Apple Mail do not count towards the sync bandwidth limit. There are separate bandwidth limits for clients and services using IMAP.

Causes

• Don't perform bulk operations using sync clients
  • Avoid large copy/paste or drag/drop operations in your email client.
  • Avoid manually resyncing the client, particularly when using Google Apps Sync. This can unnecessarily download the entire mailbox again, rather then syncing only the last chagnes.
  • For Google Apps Sync, try reducing your local mailbox size.
• Prevent continuous retries: Some email clients may retry failed actions again and again until they use up the account's bandwidth allowance. Try to recreate the profile or sync relationship on all sync clients to make sure they aren't retrying any pending actions. Try the following steps if you've exceeded the upload bandwidth limit via sync:
  • Look for messages stuck in the Outbox of any of your sync clients. Messages that are rejected by Gmail due to blocked attachments or attachment size may remain in the Outbox and repeatedly fail to be uploaded, using up bandwidth continuously.
  • Some network issues may cause clients to fail when uploading messages, making them retry repeatedly. Make sure your network connection is stable, for example by switching between mobile data and WiFi.
  • Drafts containing attachments can consume large amounts of bandwidth as they get updated when the draft is saved. Avoid unnecessary and redundant drafts.

Recommendations

• Managed your sync clients: Having multiple clients means every message gets downloaded multiple times, proportionally increasing bandwidth consumption. Remove or disable unused sync clients and quit clients when not in use. Remember that changes made on one client or the weber interface sync to all clients. So avoid making large changes if you have multiple sync clients, or decrease the amount of clients in use.
• Check for unknown/unwanted sync clients: In some cases an individual may have setup a sync client and stopped using it without disabling it. Navigate to the Google accounts authorizations page and revoke any unwanted items under Connected Sites, Apps, and Services and Application-specific passwords (if applicable).
• Use an alternative method: You can use the web interface or IMAP while you investigate sync issues, as a workaround while sync is locked out, or permanently in order to minimize sync usage.

Need additional help or have issues

For additional assistance contact the IT Services Technical Support Center via phone at (907) 786-4646, toll-free at (877) 633-3888, email us at uaa.techsupport@alaska.edu.