Please see Google's Gmail sending limits in G Suite help page for their default limits. Below, we've noted changes or additional limits managed by NPU.

Message Size

The maximum size of a G Suite message is 25 MB, including all attachments. Please note that the process of adding a file to a message increases its size (by adding encoding necessary for transmission), so if your file is almost 25 MB, you may get a "too big" error message. 


For larger files, please consider to use Google Drive.

Attachment Types

Google does not permit sending or receiving executable files (such as files with names that end in ".exe"). This includes executables that have been compressed (zipped) into files such as .zip, .tar, .tgz.

Number of Recipients

  • Using G Suite's native (web-based) interface, the maximum number of recipients for one message is 500.
  • Using G Suite through an email client, the maximum number of recipients for one message is 100.

If, in a 24-hour period, you send messages to more than 300 external recipients (that's 300 combined over however many messages you send in that period), your account will be suspended for security and compliance check, and you will not be able to send or receive mail until you contact the IT Support