MSI sales emails and communication limits

To be honest: I don't know. But I'd assume they don't - if you trigger them from Salesforce directly as "Send Email" action. If you call a Smart Campaign that sends the email, they most likely will.

Documentation also hints in that direction. It says that Comms Limits are actually limits to Smart Campaign sends but also apply to Email Program and Engagement Program sends.

https://experienceleague.adobe.com/en/docs/marketo/using/product-docs/administration/email-setup/enable-communication-limits

They should not, since MSI emails do not reach your external audience, and your external audience is the group that communication limits effect.

They don't! Check out this article: https://nation.marketo.com/t5/marketo-whisperer-blogs/how-do-communication-limits-work/ba-p/246106

1. What emails count towards communication limits?
   

Almost all emails, even operational emails are counted against communication limits. Here’s an idea in the community to exclude operational emails from communication limits. A couple notable exceptions:

• Any sales insight emails without the unsubscribe footer and alerts, or those sent through the Sales Insight email plug-ins for Outlook or Gmail.
• Marketo Mobile Engagement push notifications are not counted in communications limits, and you are not able to apply these limits to push notifications.