Curl: support multiple recipients (RCPT TO) with invalid recipients

[junho85]

I did this

There are correct address and wrong address like below

recipients = curl_slist_append(recipients, "[email protected]");
recipients = curl_slist_append(recipients, "[email protected]");

I tried to send email. but failed.

< 250 2.1.5 <[email protected]>... Recipient ok
> RCPT TO:<[email protected]>
< 550 5.1.1 RUSR 111.222.111.222: No such user: <[email protected]>
* RCPT failed: 550
> QUIT
< 221 2.0.0

I expected the following

success for sending email to [email protected] address

curl/libcurl version

7.59.0

operating system

osx 10.13.4

[bagder]

This is unfortunately a known bug, already mentioned here https://curl.haxx.se/docs/knownbugs.html#SMTP_to_multiple_recipients

Feel free to work on a fix!