PHPMailer fourth argument '-oi' does not work with some hosts with safe_mode off — at Version 1
|Reported by:||Keeslavin||Owned by:|
Description (last modified by SergeyBiryukov)
See also #20970
Some hosts (e.g. TransIP) do not accept the '-oi' parameter in the fourth argument for mail() even when safe_mode is off.
The result is that no mail can be sent through WordPress on these hosts.
Changeset  provides a partial fix when either safe_mode is off, or no sender is defined.
The parameter seems to be unnecessary, therefore it is recommended to remove this parameter. In version 3.4 and 3.4.1, it is in lines 740 and 742 of file wp-includes/class-phpmailer.php