Unable to send e-mail since April 20

[Olivia_Rust]

the linked thread does provide an alternate solution to resolve sending without an upgrade:

[Airsync] Sending email error: VersionNotSupported?

Version 9 uses AirSync for sending emails, so if you’d like to keep using version 9, you can change the sending protocol to SMTP instead, and disable AirSync calendar and contacts. Here’s the registry configuration that will do that: Windows Registry Editor Version 5.00 [HKEY_CURRENT_USER\Software\eM Client] "UseAirSyncSendMail"=dword:00000000 Copy this in a text file and save it as a .reg file, then run it. Then go to Menu > Accounts and disable AirSync under Services.