TLS and SQL Server Reporting Services: An Interesting Interaction

Thank you, Lex Thomas, for this excellent tip!

Adding the 64-bit registry keys solved a pesky issue of SSRS 2017 being unable to send data-driven subscription emails via smtp.office365.com, presumably because of recent TLS changes. I'll post the error here for search engines:

ERROR: Error sending email. Exception: System.AggregateException: One or more errors occurred. ---> System.Net.Mail.SmtpException: Failure sending mail. ---> System.IO.IOException: Unable to read data from the transport connection: net_io_connectionclosed.