CURLOPT_MAIL_RCPT_ALLLOWFAILS

CURLOPT_MAIL_RCPT_ALLLOWFAILS — Set to 1 to allow RCPT TO command to fail for some recipients which makes cURL ignore errors for individual recipients and proceed with the remaining accepted recipients. If all recipients trigger failures and this flag is specified, cURL aborts the SMTP conversation and returns the error received from to the last RCPT TO command. Replaced by CURLOPT_MAIL_RCPT_ALLOWFAILS as of cURL 8.2.0. Available as of PHP 8.2.0 and cURL 7.69.0. Deprecated as of cURL 8.2.0.

CURLOPT_MAIL_RCPT_ALLLOWFAILS = 290;