The outgoing email limits are as follows per Spacemail Terms of Service:
Trial Plans: 20 emails per hour per mailbox.
Paid Plans: 500 emails per hour per mailbox.
Please note: the limit applies to all subscriptions acquired for free until the first renewal.
It is possible to send 1 email to up to 50 recipients, including To, CC, and BCC fields.
The maximum size for email messages including attachments is set to 50 MB per email.