A multipurpose method The method works in three ways, dependent on argument value and current state 1. HELO/EHLO was not sent – returns null and set up $this->error 2. HELO was sent $name = ‘HELO’: returns server name $name = ‘EHLO’: returns boolean false $name = any string: returns null and set up $this->error 3. EHLO was sent $name = ‘HELO’|’EHLO’: returns server name $name = any string: if extension $name exists, returns boolean True or its options. Otherwise returns boolean False In other words, one can use this method to detect 3 conditions: – null returned: handshake was not or we don’t know about ext (refer to $this->error) – false returned: the requested feature exactly not exists – positive value returned: the requested feature exists
(string) (Required) Name of SMTP extension or 'HELO'|'EHLO'