Your email account includes 250 SMTP relays per mailbox, per day. Each address listed in the CC and BCC fields count against your daily limit. One relay consists of an email message sent to one address using the SMTP service. Therefore, you can send up to 250 messages per day, per mailbox. Your SMTP relay limit resets once each day, approximately every 24 hours.
If you need more than 250 relays for your mailbox, you can purchase additional relay packs (in packs of 50). You can use a maximum of 500 SMTP relays per day, per email account. If you want to use more than 500 relays per day, you can distribute SMTP relays across multiple email accounts.
The SMTP relay service is provided to you as a feature of your email account. This service is not set up by default. You must set up the service when you configure your email account settings.
With Workspace Webmail and SMTP, you are restricted to 100 email addresses (To, Cc, and Bcc) per email message, regardless of the number of SMTP relays you have per day. For more information, see Email Account Limitations and Managing Your Email Account SMTP Relays.
for more information, see Email account limitations.