On Tue, May 24, 2022 at 04:10:00PM +0100, Angus Robertson - Magenta Systems Ltd wrote: > I do see a lot of SSL connection errors in my logs, but assume these > are mostly hackers or trackers with software not able to support > TLS/1.2, usually with a blank SNI and ALPN and often no extensions in > the client hello. One had 'Versions: TLSv1.1, TLSv1.3 Key Share Data' > so got unsupported protocol. Various less popular, but still deployed SMTP servers are not updated nearly as often as desktop browsers, ... and some still support only RSA. Depending on where your users' mail comes from you may need to support RSA for SMTP. This is not a strong recommendation, but it is something to keep in mind. -- Viktor.