It’s kinda not okay that render closed outbound network traffic to SMTP ports 25, 465, and 587 for free instances without any warnings. A hidden changelog entry on September 16th for September 26th is not enough. An email should be the minimum.
We did reach out to customers who had used the identified ports in the last 30 days earlier in the month to warn of the upcoming changes so perhaps somehow you were missed.
Change log is certainly not something that we hide, we’d encourage you to subscribe to the feed so you’re kept up to date with platform changes.