Imports of package server

PathSynopsis
crypto/tlsPackage tls partially implements TLS 1.2, as specified in RFC 5246, and TLS 1.3, as specified in RFC 8446.
errorsPackage errors implements functions to manipulate errors.
github.com/emersion/go-imapPackage imap implements IMAP4rev1 (RFC 3501).
github.com/emersion/go-imap/backendPackage backend defines an IMAP server backend interface.
github.com/emersion/go-imap/commandsPackage commands implements IMAP commands defined in RFC 3501.
github.com/emersion/go-imap/responsesIMAP responses defined in RFC 3501.
github.com/emersion/go-saslLibrary for Simple Authentication and Security Layer (SASL) defined in RFC 4422.
ioPackage io provides basic interfaces to I/O primitives.
logPackage log implements a simple logging package.
netPackage net provides a portable interface for network I/O, including TCP/IP, UDP, domain name resolution, and Unix domain sockets.
osPackage os provides a platform-independent interface to operating system functionality.
syncPackage sync provides basic synchronization primitives such as mutual exclusion locks.
timePackage time provides functionality for measuring and displaying time.