Formfakten.Mail (nuget): Umbraco Package: Supports a mail cache and SSL / SMIME for .NET SmtpClient. For  	SMIME the package uses a derivation of Cpi.Net.SecureMail by Pete Everett (https://www.codeproject.com/Articles/41727/An-S-MIME-Library-for-Sending-Signed-and-Encrypted).
Keywords: Umbraco|Formfakten.Mail|Smtp|cache|SSL|SMIME