Feature #17047

Updated by c960657 (Christian Schmidt) about 2 months ago

## Proposal 
 In `Net::SMTP`, add support for parameters for `MAIL FROM` and `RCPT TO`, such as [SMTPUTF8]( and [REQUIRETLS]( 

 I suggest extending `Net::SMTP#mailfrom` and `Net::SMTP#rcpto` so they accept an additional optional Array or Hash of parameters. 

 For `Net::SMTP#send_message` and `Net::SMTP#open_message_stream`, I suggest that in addition to a String email address (or arrays of Strings), these methods should accept a pair (or arrays of pairs) of `[addr, params]`, where `addr` is the String email address, and `params` is an Array or Hash of parameters. 

 In order for the parameters to be useful, we should expose the capabilities reported by `EHLO`, so I made `capable?` public. 

 Pull request: