MailkitSender: configure using IOptionsMonitor

[gdube-nrc]

Is there a way you would accept to support reloadable options for smtp settings? MailkitSender is simple enough that I can just create another version of it that accepts IOptionsMonitor<SmtpClientOptions>, but I wonder if you'd like to have it builtin.

Perhaps a simple wrapper that gets IOptionsMonitor<SmtpClientOptions> via DI and creates a MailkitSender on send.

Note:
My use case is a blazor server-side app where the scope is long-lived (signal-r circuit).