.NET Core 3.1 support - .NET Core 3.1 is now supported on the following platforms:
Windows (x64, x86, ARM32)
Windows 10 IoT (x64, x86, ARM32)
Linux (x64, ARM32)
macOS (x64)
All: Added support for Mono 6.x.
Mail: No longer throwing an exception when parsing invalid UUEncoded data.
SMTP: Added workaround for a bug in .NET 4.0 which triggers an exception when sending email via SmtpDeliveryEngine.System with SmtpDeliveryMethod.PickupDirectory method if no host is specified.
POP3: Improved handling of Exchange-style domain+login+mailbox usernames.
IMAP: Improved handling of Exchange-style domain+login+mailbox usernames.
Networking: Added missing 'buffer' argument check to some Send/Receive methods in ProxySocket/TlsSocket.
SSH: Added a workaround for a bug introduced in OpenSSH 8.0 that rejects 'sender channel' numbers in the upper half of uint32 range.