When using Groups in the TO, CC or BCC fields for "Send Email" action, it only fetches up to 50 users

Background

Whenever using groups for the TO, CC and BCC fields in "Send Email" action in Automation rules, only up to 50 users are fetched.
The remaining users simply don't get a message.

Since this behavior is not experienced when adding more than 50 addresses directly to the TO, CC or BCC fields, this is not a limitation of the "Send Email" action, it's a bug.

Steps to reproduce

1. Create a group with more than 50 users
2. Create an automation rule with a "Send Email" action and set that group as recipient (via TO, CC or BCC fields).
3. Trigger the rule

Expected Results

All the users in the group receive the message

Actual Results

Only 50 users from that group will receive the message

Workaround

The only workarounds to the moment consist of splitting the group into multiple smaller groups (with less than 50 users each), or placing the email addresses of the target audience manually to the TO, CC and BCC fields.

Alternatively it can be automated with the use of Org REST API, but that only applies if all emails to be used are from managed accounts.