Once you upgrade to any of our Paid Plans, you will not have any “sending limits” from Let’s Calendars side, however the sending limit will now be defined by your SMTP service provider (SendGrid, Amazon SES, MailGun etc). Like for e.g. initially Amazon SES or any SMTP service imposes a per-day email sending limit in order to protect your sending reputation. The process can vary for different providers. Note: While there are not “sending limits” from Let’s Calendar’s side, each send constitutes to credit consumption and may be subjected to overage charges.